Allow to pass a callback to uploads.refresh_token()

2021-03-04 16:05:49 20822 123145562558464 ERROR    nxdrive.engine.processor Unknown error
Traceback (most recent call last):
  File "/engine/processor.py", line 337, in _execute
    self._handle_doc_pair_sync(doc_pair, sync_handler)
  File "/engine/processor.py", line 240, in _handle_doc_pair_sync
    sync_handler(doc_pair)
  File "/engine/processor.py", line 947, in _synchronize_locally_created
    fs_item_info = self.remote.stream_file(
  File "/client/remote_client.py", line 582, in stream_file
    fs_item = self.upload(
  File "/client/remote_client.py", line 446, in upload
    return uploader(self).upload(path, **kwargs)
  File "/client/uploader/sync.py", line 31, in upload
    item = self.upload_impl(file_path, command, filename=filename, **kwargs)
  File "/client/uploader/__init__.py", line 206, in upload_impl
    self.upload_chunks(transfer, blob, chunked)
  File "/client/uploader/__init__.py", line 284, in upload_chunks
    self._patch_refresh_token(uploader, transfer)
  File "/client/uploader/__init__.py", line 408, in _patch_refresh_token
    uploader.service.refresh_token = refresh
AttributeError: 'API' object attribute 'refresh_token' is read-only