Avoid "first_recent_uid 0 -> 1" errors when upgrading from v1.0 index files.
Avoid "first_recent_uid 0 -> 1" errors when upgrading from v1.0 index files.

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