Better handle 404 error as well as all other undefined scenarios
Better handle 404 error as well as all other undefined scenarios

404: now redirects to /not-found
*: now retries after 10 seconds and shows an error
   and give up after 5 minutes recommending a reload

Signed-off-by: Joas Schilling <ab43a7c9cb5b2380afc4ddf8b3e2583169b39a02@schilljs.com>

nextcloud/spreed,nextcloud/spreed,nextcloud/spreed