net/geoipupdate: switch to USES=go:modules
Switch to USES=go:modules and pass GO_ENV down to make in preparation for the
upcoming go1.16 release.
PR: 251268
Approved by: adamw (maintainer)
Update to 4.0.1
Add a MANPAGES option. If you're building this from source and don't
want to spend 2 hours on 200 ports, the manpages are the same as the
DOCS. Just use those.