Don't disable settings sync when the server is returning 403

[sandy081]

[Tyriar]

The app service is stopped atm, this should be handled gracefully (just retrying periodically like normal and don't show error to user?).

[sandy081]

Edit:

Sync should not be disabled for known failures like this eg, when server is offline or user is not authorised. Sync should be trying in the background and trying interval time should be increased.

[sandy081]

Changed the strategy:

• Do not disable the sync for known errors when server or client are offline or for unauthorised requests. Disable sync for unknown or major errors.

• In case of failures, do not change regular auto sync interval. Instead delay the sync triggered by changes or events. Sync triggered by opening or changing settings or keybindings or extensions is delayed by number of seconds as number of failures up to 1 minute.