Fix correct Scope - this fixes JS error and Chrome Ext desktop sharing for me

modules/xmpp/JingleSession.js

         self.peerconnection.addStream(new_stream);
     }
 
-    RTC.switchVideoStreams(new_stream, oldStream);
+    APP.RTC.switchVideoStreams(new_stream, oldStream);
 
     // Conference is not active
     if(!oldSdp || !self.peerconnection) {
     }
 }
 
-module.exports = JingleSession;
+module.exports = JingleSession;