Ensure town cargo bitmap correctly set after town creation

src/genworld.cpp

@@ -147,6 +147,7 @@ static void _GenerateWorld()
 					HandleGeneratingWorldAbortion();
 					return;
 				}
+				UpdateTownCargoBitmap();
 				GenerateIndustries();
 				GenerateObjects();
 				GenerateTrees();

src/town_cmd.cpp

@@ -2074,6 +2074,8 @@ CommandCost CmdFoundTown(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 			/* 't' can't be nullptr since 'random' is false outside scenedit */
 			assert(!random);
 
+			UpdateTownCargoBitmap();
+
 			if (_current_company == OWNER_DEITY) {
 				SetDParam(0, t->index);
 				AddTileNewsItem(STR_NEWS_NEW_TOWN_UNSPONSORED, NT_INDUSTRY_OPEN, tile);