If Julian is valid, we have to update the dmy representation before

If Julian is valid, we have to update the dmy representation before

1998-12-02  Havoc Pennington  <hp@pobox.com>

* gdate.c (g_date_set_month): If Julian is valid, we have to
update the dmy representation before setting the components
of it.
(g_date_set_day): Same.
(g_date_set_year): Same.