dbox: Minor optimization when creating a mailbox when its alt dir already existed. Patch by DINH Viêt Hoà
dbox: Minor optimization when creating a mailbox when its alt dir already existed.
Patch by DINH Viêt Hoà

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