QmlProjectManager: moved the no-observer warning dialog to qmlprojectplugin

Change-Id: I6ce724e0db17d22616adcdf058d1f05af7124b64
Reviewed-on: http://codereview.qt.nokia.com/1929
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

src/plugins/qmlprojectmanager/qmlprojectruncontrol.h

@@ -82,7 +82,6 @@ public:
 
 private:
     ProjectExplorer::RunControl *createDebugRunControl(QmlProjectRunConfiguration *runConfig);
-    static void showQmlObserverToolWarning();
 };
 
 } // namespace Internal