Fix: TerraGenesis was not generating maps at the requested maximum he…

…ight

- Maps were being generated with a maximum height one level lower than intended

src/tgp.cpp

@@ -235,7 +235,7 @@ static height_t TGPGetMaxHeight()
 	};
 
 	int max_height_from_table = max_height[_settings_game.difficulty.terrain_type][min(MapLogX(), MapLogY()) - MIN_MAP_SIZE_BITS];
-	return I2H(min(_settings_game.game_creation.landscape == LT_ARCTIC ? max(6, max_height_from_table) : max_height_from_table, _settings_game.construction.max_heightlevel));
+	return I2H(min(_settings_game.game_creation.landscape == LT_ARCTIC ? max(6, max_height_from_table) : max_height_from_table, _settings_game.construction.max_heightlevel + 1));
 }
 
 /**