ensure Tor daemon files have correct permissions

ensure Tor daemon files have correct permissions

Set permissions for /var/lib/tor and /var/ipfire/tor to
tor:tor, regardless whether Tor user has been created before
or not.

This ensures Tor starts properly on existing systems after
reinstallation of the add-on. Thanks to Michael for the hint.

Further, a comment for new Tor user in /etc/passwd has been added.

Fixes #11779.

Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>