maildir: Don't assert-crash if we have no read-access to the Maildir.
maildir: Don't assert-crash if we have no read-access to the Maildir.

--HG--
branch : HEAD

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