message: Convert getVisibleTile call to getTile
  Note that mTubeStart is guaranteed to be a valid position, so no
  possibility of passing a bad value to `getTile`.
diff: @@ -816,8 +816,9 @@ void MapViewState::placeTubeEnd(Tile* tile)
  bool endReach = false;
  do {
  - tile = mTileMap->getVisibleTile({mTubeStart, mTileMap->currentDepth()});
  - if (!tile) {
  + const auto tubeStartPosition = MapCoordinate{mTubeStart, mTileMap->currentDepth()};
  + tile = &mTileMap->getTile(tubeStartPosition);
  + if (!mTileMap->isVisibleTile(tubeStartPosition)) {
  endReach = true;
  }else if (tile->thing() || tile->mine() || !tile->bulldozed() || !tile->excavated()){
  endReach = true;
  