Without this patch, the user effectively cannot change the dive mode as
any change is overwritten by replot copying current_dive over
displayed_dive. The way out is not to call replot but only update the deco
ceiling directly.
Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>