Update Xandikos - RM Dead Link

README.md

@@ -276,7 +276,7 @@ _See also: [Comparison of CalDAV and CardDAV implementations - Wikipedia](https:
 - [Etebase (EteSync)](https://www.etebase.com/) - End-to-end encrypted and journaled personal information server supporting calendar and contact data, offering its own clients. ([Source Code](https://github.com/etesync/server)) `AGPL-3.0` `Python/Django`
 - [Radicale](https://radicale.org/) - Simple calendar and contact server with extremely low administrative overhead. ([Source Code](https://github.com/Kozea/Radicale)) `GPL-3.0` `Python`
 - [SabreDAV](https://sabre.io/) - Open source CardDAV, CalDAV, and WebDAV framework and server. ([Source Code](https://github.com/sabre-io/dav)) `MIT` `PHP`
-- [Xandikos](https://www.xandikos.org/) - Open source CardDAV and CalDAV server with minimal administrative overhead, backed by a Git repository. ([Source Code](https://github.com/jelmer/xandikos)) `GPL-3.0` `Python`
+- [Xandikos]https://github.com/jelmer/xandikos) - Open source CardDAV and CalDAV server with minimal administrative overhead, backed by a Git repository. `GPL-3.0` `Python`
 
 
 ### Calendar & Contacts - CalDAV or CardDAV Web-based Clients