!fix bug:update the JavaAgent link

docs/developer-guide.md

@@ -181,7 +181,7 @@ public final class YourXxxAgent {
     - [Working with Manifest Files - The Java™ TutorialsHide](https://docs.oracle.com/javase/tutorial/deployment/jar/manifestindex.html)
 - [Java SE 6 新特性: Instrumentation 新功能](http://www.ibm.com/developerworks/cn/java/j-lo-jse61/)
 - [Creation, dynamic loading and instrumentation with javaagents](http://dhruba.name/2010/02/07/creation-dynamic-loading-and-instrumentation-with-javaagents/)
-- [JavaAgent加载机制分析](http://alipaymiddleware.com/jvm/javaagent%E5%8A%A0%E8%BD%BD%E6%9C%BA%E5%88%B6%E5%88%86%E6%9E%90/)
+- [JavaAgent加载机制分析](https://www.iteye.com/blog/nijiaben-1847212/)
 
 ## Javassist