upgrade to new geoip api

[BuckarooBanzay]

Switches to the new geoip api introduced here: mt-mods/geoip#7

[S-S-X]

Probably better to fix with this now than waiting for my changes, I could push my stuff to some branch anyway to increase visibility.

[S-S-X]

FYI https://github.com/mt-mods/beowulf/tree/ac-ban WIP stuff and requires another geoip update for some caching and other stuff (forgot to push that, added #10).
And related geoip mod caching layer + prejoin hooks: https://github.com/mt-mods/geoip/tree/geoip-cache (mt-mods/geoip#10)

[S-S-X]

Probably better to fix with this now than waiting for my changes, I could push my stuff to some branch anyway to increase visibility.

Well, unless it somehow works without crashing engine. In that case could optionally wait until I manage to finish updates / testing.
(I think it already works but I've not really tested well enough and it is fairly complicated)