Update to 1.8. Move the primary download site and add MASTER_SITE_LOCAL
as a secondary (suggested by @ler).

Changes since 1.7:

• Add -x which outputs just the ip addresses seen, one per line.
• Add missing rule to match IPv6 addresses starting with :: (especially ::1).

Reviewed by: ler (mentor)
Approved by: ler (mentor)
Differential Revision: https://reviews.freebsd.org/D12752