Public share link tries to open whiteboard

[tobiasKaminsky]

On c.n.c.:

• create a public link share
• open it --> see that it opens whiteboard

[punkyard]

i confirm the issue AiO 960

[szaimen]

Looks like this might have fixed it? https://github.com/nextcloud/whiteboard/pull/201

[grnd-alt]

fixed by #201