lib-storage: Use MAIL_STORAGE_FLAG_NO_AUTOVERIFY for creating shared namespace storages. This avoids failing storage creation for nonexistent users. Previous failure made it possible for logged in users to figure out what other usernames existed on the system.
lib-storage: Use MAIL_STORAGE_FLAG_NO_AUTOVERIFY for creating shared namespace storages.
This avoids failing storage creation for nonexistent users. Previous failure
made it possible for logged in users to figure out what other usernames
existed on the system.

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