qmlobserver: Remove the changed() hack to get new object.

There is now a hook in QDeclarative itself for that.
Needs commit af2b28f9ca07057 of Qt

src/plugins/qmljsinspector/qmljsdesigndebugclient.cpp

@@ -108,8 +108,6 @@ void QmlJSDesignDebugClient::messageReceived(const QByteArray &message)
         QStringList contextPath;
         ds >> contextPath;
         emit contextPathUpdated(contextPath);
-    } else if (type == "SCENE_ITEM_COUNT_CHANGED") {
-        //emit treeRefreshRequested();
     }
 }