kuisong zheng

add this line in `discretize_one` function works for me `if not isinstance(x, list): return x `

Encountered the same problem on vs2019, I use vcpkg to install the latest python3.10 and pybind11

```bash catkin_make --only-pkg-with-deps grid_map_demos catkin_make --only-pkg-with-deps grid_map_visualization catkin_make --only-pkg-with-deps grid_map_rviz_plugin ```

@meiqua Do you solve the problem? Could you send me a patch, thanks!

@meiqua Yes, I tested it, it worked! Just check whether the goal is changed before resetting the latching. here is my [code](https://github.com/zhengzh/navigation/blob/a8aad8cba51caf2237adb9253483485a4109e703/dwa_local_planner/src/dwa_planner_ros.cpp#L151).