Change tar owner and group to just 0

It seems like some tar versions don't like the name:id form for
--owner and --group.  The closest known anonymous user being 0 (root),
that seems to be the most appropriate user/group to assign ownership
to.  It matters very little when unpacking either way.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit b91dd150)