Remove PHP-Proxy (unmaintained since 2020) (#3951)

- ref. #3558 
- `WARNING:awesome_lint.py: PHP-Proxy: last updated -1104 days, 4:54:42.041084 ago, older than 365 days`

README.md

@@ -1646,7 +1646,6 @@ _Related: [Web Servers](#web-servers)_
 - [iodine](https://code.kryo.se/iodine/) - IPv4 over DNS tunnel solution, enabling you to start up a socks5 proxy listener. ([Source Code](https://github.com/yarrick/iodine)) `ISC` `C`
 - [Nginx Proxy Manager](https://nginxproxymanager.com/) - Nginx Proxy Manager is an easy way to accomplish reverse proxying hosts with SSL termination. ([Source Code](https://github.com/jc21/nginx-proxy-manager)) `MIT` `Nodejs/Docker`
 - [Outline Server](https://getoutline.org/) - A proxy server that runs a Shadowsocks instance for each access key and a REST API to manage the access keys. ([Source Code](https://github.com/Jigsaw-Code/outline-server)) `Apache-2.0` `Docker/Nodejs`
-- [PHP-Proxy](https://www.php-proxy.com/) - Web proxy script built specifically to be fast, easy to modify and to support video sites such as YouTube. ([Demo](https://unblockvideos.com/), [Source Code](https://github.com/Athlon1600/php-proxy-app)) `MIT` `PHP`
 - [Pomerium](https://www.pomerium.io) - An identity-aware reverse proxy, successor to now obsolete oauth_proxy. It inserts an OAuth step before proxying your request to the backend, so that you can safely expose your self-hosted websites to public Internet. ([Source Code](https://github.com/pomerium/pomerium)) `Apache-2.0` `Go`
 - [Privoxy](https://www.privoxy.org) - Non-caching web proxy with advanced filtering capabilities for enhancing privacy, modifying web page data and HTTP headers, controlling access, and removing ads and other obnoxious Internet junk. `GPL-2.0` `C`
 - [sish](https://github.com/antoniomika/sish) - Open source serveo/ngrok alternative providing HTTP(S)/WS(S)/TCP tunnels to localhost using only SSH. `MIT` `Go`