detectChange causes an erroneous log message in dev modeon Play start

[xael-fry]

Report by @selangley 1a0f924#commitcomment-19419445

This causes an erroneous log message in dev mode:
ERROR play - Restart: Need to restart Play because \application.conf has been changed

because when detectChange() is first executed the value of long configLastModified has not been properly initialized yet. It's value is 0. So the ConfigurationChangeWatcherPlugin will think a change has occurred to the application.conf when it it fact has not occurred. The value of configLastModified only gets initialized later when onConfigurationRead() is called.

Here is a snippet from my log file showing the order in which these methods were called:

17:51:19,355 INFO play:308 - detectChange()
java.lang.Throwable
at play.ConfigurationChangeWatcherPlugin.detectChange(ConfigurationChangeWatcherPlugin.java:24)
at play.plugins.PluginCollection.detectChange(PluginCollection.java:598)
at play.Play.detectChanges(Play.java:641)
at play.Invoker$Invocation.init(Invoker.java:199)
at play.server.PlayHandler$NettyInvocation.init(PlayHandler.java:264)
at play.Invoker$Invocation.run(Invoker.java:285)

17:51:19,474 INFO play:308 - onConfigurationRead()
java.lang.Throwable
at play.ConfigurationChangeWatcherPlugin.onConfigurationRead(ConfigurationChangeWatcherPlugin.java:14)
at play.plugins.PluginCollection.onConfigurationRead(PluginCollection.java:610)
at play.Play.readConfiguration(Play.java:356)
at play.Play.start(Play.java:489)
at play.Play.detectChanges(Play.java:659)
at play.Invoker$Invocation.init(Invoker.java:199)
at play.server.PlayHandler$NettyInvocation.init(PlayHandler.java:264)
at play.Invoker$Invocation.run(Invoker.java:285)
at play.server.PlayHandler$NettyInvocation.run(PlayHandler.java:303)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)