refactor(apollo-common): 优化异常处理信息展示

Author: youngzil

Diff for: CHANGES.md

@@ -9,6 +9,7 @@ Apollo 2.5.0
 * [Feature: Provide a new configfiles API to return the raw content of configuration files directly](https://github.com/apolloconfig/apollo/pull/5336)
 * [Feature: Enhanced instance configuration auditing and caching](https://github.com/apolloconfig/apollo/pull/5361)
 * [Feature: Provide a new open API to return the organization list](https://github.com/apolloconfig/apollo/pull/5365)
+* [Refactor: Exception hander adds root cause information](https://github.com/apolloconfig/apollo/pull/5367)
 
 ------------------
 All issues and pull requests are [here](https://github.com/apolloconfig/apollo/milestone/16?closed=1)

Diff for: apollo-common/src/main/java/com/ctrip/framework/apollo/common/controller/GlobalDefaultExceptionHandler.java

@@ -175,7 +175,7 @@ private String getMessageWithRootCause(Throwable ex) {
     String message = ex.getMessage();
     Throwable rootCause = NestedExceptionUtils.getMostSpecificCause(ex);
     if (rootCause != ex) {
-      message += "; rootCause message " + rootCause.getMessage();
+      message += " [Cause: " + rootCause.getMessage() + "]";
     }
     return message;
   }