lib-index: When index is reset, make sure old dovecot.index gets deleted.
lib-index: When index is reset, make sure old dovecot.index gets deleted.

--HG--
branch : HEAD

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