window: Avoid double event processing in the multipress event controller

The events to those are fed outside the regular event propagation scheme,
through _gtk_window_check_handle_wm_event(), so set the controller to
GTK_PHASE_NONE so events aren't processed first manually, and then
automatically.

gtk/gtkwindow.c

@@ -1595,8 +1595,6 @@ gtk_window_constructor (GType                  type,
                         G_CALLBACK (multipress_gesture_pressed_cb), object);
       g_signal_connect (priv->multipress_gesture, "stopped",
                         G_CALLBACK (multipress_gesture_stopped_cb), object);
-      gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (priv->multipress_gesture),
-                                                  GTK_PHASE_CAPTURE);
     }
 
   return object;