fixed settings for tray message enable/disable

now it can be enabled and disabled at runtime

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@3141 b45a01b8-16f6-495d-af2f-9b41ad6348cc

retroshare-gui/src/gui/MainWindow.h

@@ -134,6 +134,7 @@ public:
 #endif
     PluginsPage*   pluginsPage ;
 
+    static void installGroupChatNotifier();
 
 public slots:
     void updateHashingInfo(const QString&) ;