remove sipxcom

- website not responding/timeout
- unmaintained since 2021
- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/2266

README.md

@@ -502,7 +502,6 @@ Simple deployment of [E-mail](https://en.wikipedia.org/wiki/Email) servers, e.g.
 - [Routr](https://routr.io) - A lightweight sip proxy, location server, and registrar for a reliable and scalable SIP infrastructure. ([Source Code](https://github.com/fonoster/routr)) `MIT` `Docker`
 - [SIP3](https://sip3.io/) - VoIP troubleshooting and monitoring platform. ([Demo](https://demo.sip3.io), [Source Code](https://github.com/sip3io/)) `Apache-2.0` `Kotlin`
 - [SIPCAPTURE Homer](https://www.sipcapture.org/) - Troubleshooting and monitoring VoIP calls. ([Source Code](https://github.com/sipcapture/homer)) `AGPL-3.0` `Angular/C`
-- [SipXcom](https://sipxcom.org/) - Open source unified communications system. ([Source Code](https://github.com/sipXcom/sipxecs)) `AGPL-3.0` `Java`
 - [Wazo](https://wazo-platform.org/) - Full-featured IPBX solution built atop Asterisk with integrated Web administration interface and REST-ful API. ([Source Code](https://github.com/wazo-platform)) `GPL-3.0` `Python`
 - [Yeti-Switch](https://yeti-switch.org/) - Transit class4 softswitch(SBC) with integrated billing and routing engine and REST API. ([Demo](https://yeti-switch.org/demo.html), [Source Code](https://github.com/yeti-switch)) `GPL-2.0` `C++/Ruby`