[macOS] Handle unsupported command 'nxdrive://trigger-watch' in protocol handler

Problem

Sentry Issue: NUXEO-DRIVE-537

ValueError: Unsupported command 'nxdrive://trigger-watch' in protocol handler
  File "nxdrive/gui/application.py", line 1544, in event
  File "nxdrive/gui/application.py", line 1563, in _handle_nxdrive_url
  File "nxdrive/utils.py", line 723, in parse_protocol_url

Error handling URL event 'nxdrive://trigger-watch'

Analysis

Happens when doing an update from 3.1.2 to 5.2.0. After a successful upgrade, the old FInderSync extension keep running into the background and send outdated commands to Drive that can't be understood anymore.

Fix

These outdated commands are now simply ignored and the user should restart the OS to kill the old FinderSync extension.