Possible one more performance increasing

Lets try to use own QueuedConnection type instead of default
AutoConnection. To implement it we need to disconnect all default slots
and reconnect them with specified connection type

sources/awesome-widget/plugin/awdataengineaggregator.h

@@ -44,6 +44,7 @@ public slots:
     void reconnectSources(const int interval);
 
 private:
+    void createQueuedConnection();
     Plasma::DataEngineConsumer *m_consumer = nullptr;
     QHash<QString, Plasma::DataEngine *> m_dataEngines;
 };