martin f. krafft <madduck@madduck.net> [Fri, 13 Apr 2012 17:49:14 +0200] rev 530
Modify SQL update script to accept NULL fields for users
The value NULL in the qid/ssid/tid fields of the user table means that the
value from the associated domain record should be used instead.
This patch modifies the PL/pgSQL functions used by Dovecot and Postfix
accordingly.