When extracting geoip and geoip6 files from MaxMind's GeoLite2 Country
database, we only look at country->iso_code which is the two-character ISO
3166-1 country code of the country where MaxMind believes the end user is
located.
But if MaxMind thinks a range belongs to anonymous proxies, they don't put
anything there. Hence, we omit those ranges and resolve them all to '??'.
That's not what we want.
What we should do is first try country->iso_code, and if there's no such
key, try registered_country->iso_code which is the country in which the
ISP has registered the IP address.
In short: let's fill all A1 entries with what ARIN et. al think.
If the cert turns out to be invalid or if wget is otherwise unable to
verify it, it's going to return an error and not download the file for us.
Spotted by nickm.
The latest GeoLite2 database includes a pointer from 2001::/32 to the root
node of the IPv4 address space in the tree. We need to exclude this whole
address space from geoip6, similar to how we exclude IPv4-mapped IPv6
addresses and the 6to4 mapping subnet.
