Codechange: pass the randomizer directly to the town name generation

src/tree_cmd.cpp

@@ -308,6 +308,7 @@ void PlaceTreesRandomly()
  */
 uint PlaceTreeGroupAroundTile(TileIndex tile, TreeType treetype, uint radius, uint count, bool set_zone)
 {
+	assert(_game_mode == GM_EDITOR); // Due to InteractiveRandom being used in this function
 	assert(treetype < TREE_TOYLAND + TREE_COUNT_TOYLAND);
 	const bool allow_desert = treetype == TREE_CACTUS;
 	uint planted = 0;