set_logger_callback(None) does not work

[wonder-sk]

It is not possible to set no logger callback with the python API:

  File "test.py", line 36, in __init__
    self.geodiff.set_logger_callback(None)
  File "/usr/local/lib/python3.8/dist-packages/pygeodiff-2.0.1-py3.8-linux-x86_64.egg/pygeodiff/main.py", line 33, in set_logger_callback
    return self.clib.set_logger_callback(callback)
  File "/usr/local/lib/python3.8/dist-packages/pygeodiff-2.0.1-py3.8-linux-x86_64.egg/pygeodiff/geodifflib.py", line 180, in set_logger_callback
    self.callbackLogger = cFuncType(callback)
TypeError: argument must be callable or integer function address