Trees appear immedeately after a buidling is destroyed

[KroArtem]

My catapult just destroyed town hall and a square of tree appeared immediately on the place it stood. There is also a shell-hole on those place, see screenshot.

[Andrettin]

Thank you! I've made it so now the "regeneration counter" remains at 0 when the tile is occupied by a building (previously the counter advanced, but the regeneration itself was stopped if the tile was occupied), to avoid this sort of situation: https://github.com/Andrettin/Wyrmgus/commit/e27145f94614cb6e6be40229488231f2027b46fe