when a resizing configure event is throttled (skipped to limit redraws
to once per vblank) the xdg_surface serial was never acknowledged. the
early return bypassed the ack_configure call that follows the throttle
check, violating the xdg-shell protocol requirement that every configure
serial be acknowledged before the next surface commit.

fix by calling ack_configure before the early return so the compositor
always receives the acknowledgment, dosent matter whether the resize
itself is applied.

Release Notes:

- N/A