remove old link when editing

[grnd-alt]

Fixes #5516

[max-nextcloud]

The current change works well when only changing a single link in a paragraph. There are two more scenarios that would be good to account for:

Link in a paragraph

Find more information on https://nextcloud.com as usual.

-> should only change the link.

Link with custom text

More informarion

-> should only change the href.