autocreate plugin: If mail_debug=yes, log the reason why mailbox creation fails.
autocreate plugin: If mail_debug=yes, log the reason why mailbox creation fails.

--HG--
branch : HEAD

jwm/dovecot-notmuch,jkerihuel/dovecot,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jkerihuel/dovecot,jwm/dovecot-notmuch,jkerihuel/dovecot,jwm/dovecot-notmuch,jkerihuel/dovecot,jkerihuel/dovecot