Only declare the actual changed session of a user as changed
Only declare the actual changed session of a user as changed

Before all sessions of a user where seen as changed, instead of
only the one session that actually was changed.
It is a regression from introducing multi-session support I assume.

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

nextcloud/spreed,nextcloud/spreed,nextcloud/spreed