🐛 #1861【微信支付】支付分后付费项目请求类的amount属性改为Integer，允许为空

Author: winter4666

weixin-java-pay/src/main/java/com/github/binarywang/wxpay/bean/payscore/PostPayment.java

@@ -26,7 +26,7 @@ public class PostPayment implements Serializable {
   @SerializedName("name")
   private String name;
   @SerializedName("amount")
-  private int amount;
+  private Integer amount;
   @SerializedName("description")
   private String description;
   @SerializedName("count")