spring-cloud-gateway配合apollo做动态路由，删除路由时报错

[thisisgpy]

SpringCloud 版本：Greenwich.SR4
SpringBoot 版本：2.1.11.RELEASE
Apollo Client 版本：1.5.0

代码完全 Copy 的官方提供的 demo，测试发现在运行时可以增加和修改路由，但删除路由则会报错。完整报错信息如下：

org.springframework.boot.context.properties.ConfigurationPropertiesBindException: Error creating bean with name 'gatewayProperties': Could not bind properties to 'GatewayProperties' : prefix=spring.cloud.gateway, ignoreInvalidFields=false, ignoreUnknownFields=true; nested exception is org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'spring.cloud.gateway.routes' to java.util.List<org.springframework.cloud.gateway.route.RouteDefinition>
	at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.bind(ConfigurationPropertiesBindingPostProcessor.java:104)
	at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:89)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:414)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1763)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:405)
	at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.rebind(ConfigurationPropertiesRebinder.java:102)
	at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.rebind(ConfigurationPropertiesRebinder.java:83)
	at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.onApplicationEvent(ConfigurationPropertiesRebinder.java:128)
	at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.onApplicationEvent(ConfigurationPropertiesRebinder.java:50)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:402)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:359)
	at com.ganpengyu.demo.gateway.cloud.config.DynamicRoutesRefresher.refreshGatewayProperties(DynamicRoutesRefresher.java:66)
	at com.ganpengyu.demo.gateway.cloud.config.DynamicRoutesRefresher.onChange(DynamicRoutesRefresher.java:52)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:282)
	at com.ctrip.framework.apollo.spring.annotation.ApolloAnnotationProcessor$1.onChange(ApolloAnnotationProcessor.java:63)
	at com.ctrip.framework.apollo.internals.AbstractConfig$2.run(AbstractConfig.java:449)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'spring.cloud.gateway.routes' to java.util.List<org.springframework.cloud.gateway.route.RouteDefinition>
	at org.springframework.boot.context.properties.bind.Binder.handleBindError(Binder.java:242)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:218)
	at org.springframework.boot.context.properties.bind.Binder.lambda$bindBean$3(Binder.java:322)
	at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:80)
	at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:70)
	at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:54)
	at org.springframework.boot.context.properties.bind.Binder.lambda$null$4(Binder.java:329)
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
	at java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1359)
	at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:126)
	at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:499)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:486)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472)
	at java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:152)
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:464)
	at org.springframework.boot.context.properties.bind.Binder.lambda$bindBean$5(Binder.java:330)
	at org.springframework.boot.context.properties.bind.Binder$Context.withIncreasedDepth(Binder.java:429)
	at org.springframework.boot.context.properties.bind.Binder$Context.withBean(Binder.java:415)
	at org.springframework.boot.context.properties.bind.Binder$Context.access$400(Binder.java:372)
	at org.springframework.boot.context.properties.bind.Binder.bindBean(Binder.java:328)
	at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:269)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:214)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:202)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:185)
	at org.springframework.boot.context.properties.ConfigurationPropertiesBinder.bind(ConfigurationPropertiesBinder.java:78)
	at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.bind(ConfigurationPropertiesBindingPostProcessor.java:101)
	... 27 common frames omitted
Caused by: org.springframework.boot.context.properties.bind.UnboundConfigurationPropertiesException: The elements [spring.cloud.gateway.routes[1].filters[0],spring.cloud.gateway.routes[1].id,spring.cloud.gateway.routes[1].predicates[0],spring.cloud.gateway.routes[1].uri] were left unbound.
	at org.springframework.boot.context.properties.bind.IndexedElementsBinder.assertNoUnboundChildren(IndexedElementsBinder.java:136)
	at org.springframework.boot.context.properties.bind.IndexedElementsBinder.bindIndexed(IndexedElementsBinder.java:113)
	at org.springframework.boot.context.properties.bind.IndexedElementsBinder.bindIndexed(IndexedElementsBinder.java:86)
	at org.springframework.boot.context.properties.bind.IndexedElementsBinder.bindIndexed(IndexedElementsBinder.java:71)
	at org.springframework.boot.context.properties.bind.CollectionBinder.bindAggregate(CollectionBinder.java:49)
	at org.springframework.boot.context.properties.bind.AggregateBinder.bind(AggregateBinder.java:56)
	at org.springframework.boot.context.properties.bind.Binder.lambda$bindAggregate$2(Binder.java:293)
	at org.springframework.boot.context.properties.bind.Binder$Context.withIncreasedDepth(Binder.java:429)
	at org.springframework.boot.context.properties.bind.Binder$Context.access$100(Binder.java:372)
	at org.springframework.boot.context.properties.bind.Binder.bindAggregate(Binder.java:293)
	at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:254)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:214)
	... 52 common frames omitted