GNUnet switched to git

Also fixed capitalization of its name.

README.md

@@ -221,7 +221,7 @@ Some [Groupware](#groupware) solutions also feature calendar/address book editin
   * [Cherry](https://github.com/rafael-santiago/cherry) - A tiny webchat server. `GPLv2` `Go`
   * [Freenet](https://freenetproject.org/index.html) - Anonymously share files, browse and publish "freesites" (web sites accessible only through Freenet) and chat on forums. ([Source Code](https://github.com/freenet/fred)) `GPLv2` `Java`
   * [Friends](http://moose-team.github.io/friends/) - P2P chat powered by the web. ([Source Code](https://github.com/moose-team/friends)) `MIT` `Nodejs`
-  * [GNUNet](https://gnunet.org/) - Free software framework for decentralized, peer-to-peer networking. ([Source Code](https://gnunet.org/svn/)) `GPLv3` `C`
+  * [GNUnet](https://gnunet.org/) - Free software framework for decentralized, peer-to-peer networking. ([Source Code](https://gnunet.org/git/)) `GPLv3` `C`
   * [hack.chat](https://hack.chat/) - A minimal, distraction-free chat application. ([Source Code](https://github.com/AndrewBelt/hack.chat)) `GPLv3` `Nodejs`
   * [Hawkpost](https://hawkpost.co) - HawkPost is a web app that lets you create unique links that you can share with a person that desires to send you important information but doesn't know how to encrypt it. The message is encrypted in their browser and sent to your email address. ([Source Code](https://github.com/whitesmith/hawkpost)) `MIT` `Python`
   * [Hubl.in](https://hubl.in/) - WebRTC powered video conference, chat and collaborative editor. ([Source Code](https://github.com/linagora/hublin)) `AGPLv3` `Nodejs`