[macOS] Use EAFP to catch FileNotFoundError in send_content_sync_status()

2019-06-27 09:53:58 351 4718020032 ERROR    nxdrive.osi.darwin.darwin Error while trying to send status to FinderSync
Traceback (most recent call last):
  File "osi/darwin/darwin.py", line 250, in send_content_sync_status
  File "osi/darwin/darwin.py", line 250, in <listcomp>
  File "osi/extension.py", line 134, in get_formatted_status
  File ".../pathlib.py", line 1158, in stat
  File ".../pathlib.py", line 387, in wrapped
FileNotFoundError: [Errno 2] No such file or directory: '/Users/user/folder/file.pptx'