Lock dispatchLock before the regular lock

Fixes deadlock

Task-number: QTBUG-44836
Change-Id: Ie6def2d1e9684f4272d8920cd19c5765eef5f7c9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbusconnection.cpp

@@ -700,6 +700,7 @@ bool QDBusConnection::connect(const QString &service, const QString &path, const
         return false;
     }
 
+    QDBusDispatchLocker dispatchLocker(ConnectAction, d);
     QDBusWriteLocker locker(ConnectAction, d);
     return d->connectSignal(service, path, interface, name, argumentMatch, signature, receiver, slot);
 }