Automatically start XSwiftBus

In the past, XSwiftBus required to be started from the menu. This was a
historic behaviour since it made it possible to start it with different
DBus connection options. Since those are now moved into a config file,
it can be started right away.

src/xswiftbus/plugin.h

@@ -81,7 +81,7 @@ namespace XSwiftBus
         bool m_shouldStop = false;
 
         void readConfig();
-        void startServer(CDBusConnection::BusType bus);
+        void startServer();
         void switchToOwnAircraftView();
 
         static float flightLoopCallback(float, float, int, void *refcon);