Release v3.31.0-beta.2 (#2168)

Improvements for all users:

• We will now automatically refresh the app's OAuth client when it expires on
  any request. This should prevent synchronization errors and avoid the need for
  restarting the app in such cases.
• We have improved the performance of the initial remote changes fetch which
  could be slow enough on old Cozy to fail.
• We've tweaked the app's status update to make it less likely to show an
  "up-to-date" status while we're actually fetching changes from the Cozy.

See also known issues.

Happy syncing!