add forward_server_srs example to conf/forward.master.conf

@@ -9,4 +9,6 @@ daemon              off;
 srs_log_tank        console;
 vhost __defaultVhost__ {
     forward         127.0.0.1:19350;
+#the forward destination server type,default true. if the server is not srs server,connect app maybe fail,try config as false 
+    forward_server_srs  true;
 }