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.

damoxc/dovecot,damoxc/dovecot,damoxc/dovecot,damoxc/dovecot,damoxc/dovecot