main/varnish: cleaning

Hi,

The current APKBUILD for varnish could be lightened up a bit. I'm ready to open a PR for that but I wanted to check if there was interest first.

What I have in mind

• no need for patches anymore, alpine compilation has been integrated in the CI for a while now, so there's no need for downstream changes
• incorporate the same varnishreload as the other packages, which is sorely missed in the official package
• this last one may be a bit controversial, but I would get rid of the varnish-geoip package, running inline-C in production is really a bad idea, specially when there are vmods to do it in a much cleaner fashion

For info, I maintain a stripped-down version of the official APKBUILD here which is used for the docker hub images. It's probably too bare to be official though (no *.initd nor *.confd).