If extension record was tried to be updated for uid=0, log an error instead of crashing. Also log error if uid >= next_uid.
If extension record was tried to be updated for uid=0, log an error instead
of crashing. Also log error if uid >= next_uid.

--HG--
branch : HEAD

dscho/dovecot,dscho/dovecot,dscho/dovecot,dscho/dovecot,dscho/dovecot