msginit: Remove obsolete country codes
* gettext-tools/src/msginit.c (catalogname_for_locale): Remove sr_YU,
which were removed from ISO 3166-1:1997. Add comment saying that
pap_AN, which were removed from ISO 3166-1:2006, can be removed in the
future.
Reported by Jakub Wilk in:
<https://lists.gnu.org/archive/html/bug-gettext/2015-06/msg00057.html>.
