Google Drive source file processing fails due to missing lastModifyingUser.photoLink field

The following access to the lastModifyingUser.photoLink field fails

Line 184 in 20d0245

author_image_url=file['lastModifyingUser']['photoLink'],

2023-03-27 09:26:51,039 | INFO | google_drive.py:140 | processing file ********************
2023-03-27 09:26:52,481 | ERROR | base_data_source.py:95 | Error while indexing data source
Traceback (most recent call last):
  File "/app/data_source_api/base_data_source.py", line 93, in index
    self._feed_new_documents()
  File "/app/data_sources/google_drive.py", line 199, in _feed_new_documents
    self._index_files_from_drive(drive)
  File "/app/data_sources/google_drive.py", line 184, in _index_files_from_drive
    author_image_url=file['lastModifyingUser']['photoLink'],
KeyError: 'photoLink'

Google's documentation mentions that it may not be defined:
lastModifyingUser.photoLink string A link to the user's profile photo, if available.

thanks