update readme

@@ -11,7 +11,7 @@ see also: [http://winlinvip.github.io/simple-rtmp-server](http://winlinvip.githu
 ### Contributors
 winlin([winterserver](#)): [http://blog.csdn.net/win_lin](http://blog.csdn.net/win_lin) <br/>
 wenjie([wenjiegit](https://github.com/wenjiegit/simple-rtmp-server)): [http://blog.chinaunix.net/uid/25006789.html](http://blog.chinaunix.net/uid/25006789.html) <br/>
-who is the contributors: <br/>
+about the contributors: <br/>
 1. contribute important features to srs. <br/>
 2. the name of all contributors will send in the response of NetConnection.connect and metadata.