update readme, refine the title

 #Simple-RTMP-Server
 
-下载发布版(github): [Centos6-x86_64](http://winlinvip.github.io/srs.release/releases/files/SRS-CentOS6-x86_64-0.9.30.zip) [alternative downloads](http://winlinvip.github.io/srs.release/releases/)
+下载发布版(github): [Centos6-x86_64](http://winlinvip.github.io/srs.release/releases/files/SRS-CentOS6-x86_64-0.9.30.zip) 其他[more...](http://winlinvip.github.io/srs.release/releases/)
 
-下载发布版(国内阿里云镜像): [Centos6-x86_64](http://demo.chnvideo.com:8085/srs/releases/files/SRS-CentOS6-x86_64-0.9.30.zip) [alternative downloads](http://demo.chnvideo.com:8085/srs/releases/)
+下载发布版(国内阿里云镜像): [Centos6-x86_64](http://demo.chnvideo.com:8085/srs/releases/files/SRS-CentOS6-x86_64-0.9.30.zip) 其他[more...](http://demo.chnvideo.com:8085/srs/releases/)
 
 获得源码(github): [simple-rtmp-server](https://github.com/winlinvip/simple-rtmp-server)
 

@@ -27,8 +27,11 @@ product_dir=$work_dir
 ret=$?; if [[ $ret -ne 0 ]]; then exit $ret; fi
 ok_msg "导入脚本成功"
 
+git remote -v|grep code.csdn.net >/dev/null 2>&1
+ret=$?; if [[ 0 -ne $ret ]]; then failed_msg "当前分支不是CSDN镜像"; exit 0; fi 
+
 for ((;;)); do
-    git checkout srs.master && git pull
+    git checkout srs.master && git pull 
     ret=$?; if [[ 0 -ne $ret ]]; then 
         failed_msg "更新github分支失败，自动重试";
         continue