lib-storage: If read-only mailbox uses private flags, don't return it as READ-ONLY.
lib-storage: If read-only mailbox uses private flags, don't return it as READ-ONLY.

--HG--
branch : HEAD

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