Broken link in description after the attachment is deleted

Describe the bug
In the description of a card the link of an inserted attachment is broken, after the attachment is deleted

To Reproduce

1. Attach a file to a card
2. Insert the attachment (test_attachment.txt) into description
3. Delete the attachment
4. Wait until the attachment is finally deleted and the icon for undelete is disappeared
5. Open the card and click on the link "???? test_attachment.txt", which refers to (/nextcloud/apps/deck/cards/188/attachment/42)
6. The nextcloud errorpage "Internal Server Error; The server was unable to complete your request.; If this happens again, ..." is displayed

Expected behavior
In the description is only the text "???? test_attachment.txt" or "???? missing attachment: test_attachment.txt" and no clickable link, which refers to the deleted file

Tested with
0.4.0-beta3

Note
Perhaps the behavior depends on the extension of the deleted file. With textfiles there is a broken link, with images it is just like expected "???? test_attachment.jpg" (without link)

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Start by reproducing the issue from a card description using the attachment URL /nextcloud/apps/deck/cards/188/attachment/42, then inspect how deleted attachments are handled when the description is opened. Compare the text-file behavior with the image behavior; done means a deleted attachment is rendered as non-clickable text rather than producing an internal server error.