Make sure we don't use a stale first_unwritten_pos to optimize dovecot-uidlist writing.
Make sure we don't use a stale first_unwritten_pos to optimize
dovecot-uidlist writing.

--HG--
branch : HEAD

jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jkerihuel/dovecot,jwm/dovecot-notmuch,jkerihuel/dovecot,jkerihuel/dovecot,jkerihuel/dovecot,jkerihuel/dovecot