[Dovecot] Bug: maildirsize not updated when deleting folders

When using maildir++ quotas, if you delete an IMAP folder, the maildirsize file should get updated so that it subtracts the size of the messages that were contained in the deleted IMAP folder. However Dovecot is not doing this, resulting in Dovecot showing an incorrect quota value until the next time the maildirsize file is rebuilt.

Bill