[Bug]: Failed to load notifications when a board deleted

[luka-nextcloud]

Describe the bug
If a remain notification related to a deleted board, loading notifications will return error:

Internal Server Error\nDid expect one result but found none when executing: query \"SELECT * FROM `*PREFIX*deck_boards` WHERE (`id` = :dcValue2) AND (`deleted_at` = :dcValue1) ORDER BY `id` ASC\";

To Reproduce
Steps to reproduce the behavior:

1. Login as user A

1. Enable Deck notification A board, list or card was changed
2. Create a Board1
3. Share Board1 to user B

2. Login as user B

2. Rename Board1

3. Login as user A

1. See notification that Board1 has been renamed
2. Delete Board1
3. Reload notifications list

Expected behavior
The notifications are loaded successfully.