window: Don't constrain an acked window geometry

In Wayland, window configuration is asynchronous. Window geometry is
constrained, the constrained geometry is sent to the client, and the
client will adapt its surface and acknowledge the configuration. When
acknowledged, we shouldn't reconstrain again, as that may invalidate the
constraint calculated for the configured size.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/907

src/core/window.c

@@ -4085,6 +4085,7 @@ meta_window_move_resize_internal (MetaWindow          *window,
 
   constrained_rect = unconstrained_rect;
   if (flags & (META_MOVE_RESIZE_MOVE_ACTION | META_MOVE_RESIZE_RESIZE_ACTION) &&
+      !(flags & META_MOVE_RESIZE_WAYLAND_FINISH_MOVE_RESIZE) &&
       window->monitor)
     {
       MetaRectangle old_rect;