remove RedBird (unmaintained since 2020)

- ref. #3558
- ref. https://github.com/OptimalBits/redbird/issues/267

README.md

@@ -1651,7 +1651,6 @@ _Related: [Web Servers](#web-servers)_
 - [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`
-- [Redbird](https://github.com/OptimalBits/redbird) - A modern reverse proxy for node that includes cluster, HTTP2, LetsEncrypt, and Docker support. `BSD-2-Clause` `Javascript`
 - [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`
 - [socks5-proxy-server](https://github.com/nskondratev/socks5-proxy-server) - SOCKS5 proxy server with built-in authentication and Telegram-bot for user management and user statistics on data spent (handy when you pay per GB of data). It is dockerised and simple to install. `Apache-2.0` `Nodejs`
 - [Squid](http://www.squid-cache.org/) - Caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. ([Source Code](https://code.launchpad.net/squid)) `GPL-2.0` `C`