Update GoatCounter license and tagline

I changed the license from AGPL to EUPL quite a while ago, and also
update the tagline (it's "easy to use", but hardly "simple"; they're 2
different things).

README.md

@@ -115,7 +115,7 @@ _Web Analytics_
 - [Fathom Analytics](https://github.com/usefathom/fathom) - Simple & trustworthy website analytics. `MIT` `Go`
 - [Freshlytics](https://github.com/sheshbabu/freshlytics) - Privacy respecting, cookie free and low resource usage analytics platform. `MIT` `Docker/Nodejs`
 - [GoAccess](http://goaccess.io/) - Real-time web log analyzer and interactive viewer that runs in a terminal. ([Source Code](https://github.com/allinurl/goaccess)) `GPL-2.0` `C`
-- [GoatCounter](https://www.goatcounter.com) - Simple web statistics. No tracking of personal data. ([Source Code](https://github.com/zgoat/goatcounter)) `AGPL-3.0` `Go`
+- [GoatCounter](https://www.goatcounter.com) - Easy web statistics. No tracking of personal data. ([Source Code](https://github.com/zgoat/goatcounter)) `EUPL-1.2` `Go`
 - [Hastic](https://hastic.io) - Hackable time series pattern recognition tool with UI for Grafana. ([Source Code](https://github.com/hastic)) `Apache-2.0` `Python/Nodejs`
 - [KISSS](https://kis3.dev) - Very minimalistic (KISS) website statistics tool. ([Source Code](https://github.com/kis3/kis3)) `MIT` `Go`
 - [Koko Analytics](https://www.kokoanalytics.com/) - Privacy-friendly and open source analytics plugin for WordPress. ([Source Code](https://github.com/ibericode/koko-analytics/)) `GPL-3.0` `PHP`