Stop ExH syncs from starting when there's a cookie/login issue

[zerpiente]

Describe your suggested feature

When a user updates their ExH favourites while there's a cookie/login issue, the sync will trash their sync state.

So after fixing the issue by logging in again, following syncs will try to sync all the favorites intead of doing an incremental sync.

This is notably bad for big galleries, since this might mean days of syncing.

To avoid this I suggest that syncs are not allowed to start at all if there is a cookie/login issue

Other details

No response

Acknowledgements

• I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open or closed issue.
• I have written a short but informative title.
• I have updated the app to version 1.11.0.
• I will fill out all of the requested information in this form.