Only delete users that are guests as actor type not participant type
Only delete users that are guests as actor type not participant type

So PINs are retained when a user hangs up the phone

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

nextcloud/spreed,nextcloud/spreed,nextcloud/spreed