indexer: When worker disconnects, forget which user it was attached to. This fixes an assert crash.
indexer: When worker disconnects, forget which user it was attached to.
This fixes an assert crash.

LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot