Remove LNDMC_ALT_MAX

This should be replaced with the maximum geofence
altitude GF_MAX_VER_DIST. I'm not aware anyone is using
this functionality as is.

src/modules/navigator/land.cpp

@@ -58,7 +58,6 @@ Land::on_activation()
 	/* convert mission item to current setpoint */
 	struct position_setpoint_triplet_s *pos_sp_triplet = _navigator->get_position_setpoint_triplet();
 	pos_sp_triplet->previous.valid = false;
-	mission_apply_limitation(_mission_item);
 	mission_item_to_position_setpoint(_mission_item, &pos_sp_triplet->current);
 	pos_sp_triplet->next.valid = false;