dsync: Allow syncing same mail root dirs if indexes are different. Fixes dsyncing with storages that have no mail root dirs.
dsync: Allow syncing same mail root dirs if indexes are different.
Fixes dsyncing with storages that have no mail root dirs.

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