KeyError in case input datasets do not have WGS84 as geographic datum

This was raised in case the input datasets have EPSG:3035 as projection:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\conda\arosics\lib\site-packages\arosics\CoReg.py", line 1330, in calculate_spatial_shifts
    self._get_updated_map_info()
  File "C:\conda\arosics\lib\site-packages\arosics\CoReg.py", line 1341, in _get_updated_map_info
    original_map_info = geotransform2mapinfo(self.shift.gt, self.shift.prj)
  File "C:\conda\arosics\lib\site-packages\py_tools_ds\geo\map_info.py", line 216, in geotransform2mapinfo
    return Geocoding(gt=gt, prj=prj).to_mapinfo()
  File "C:\conda\arosics\lib\site-packages\py_tools_ds\geo\map_info.py", line 49, in __init__
    self.from_geotransform_projection(gt, prj)
  File "C:\conda\arosics\lib\site-packages\py_tools_ds\geo\map_info.py", line 111, in from_geotransform_projection
    self.datum = 'WGS-84' if proj4['datum'] == 'WGS84' else proj4['datum']  # proj4['ellps']?
KeyError: 'datum'