fix(RSS2Email): Change project link

The project link http://www.allthingsrss.com/rss2email/ is not working
anymore, according to the project on GitHub
https://github.com/turbodog/rss2email, it is not maintained anymore.

There is a new fork (https://github.com/wking/rss2email) which is the
current project and there is no official webpage, therefore, it's better
to leave the GitHub project link as the main one.

Signed-off-by: Rodrigo Avelino <rodrigo@avelino.org>

README.md

@@ -683,7 +683,7 @@ _RSS/Atom automation_
 - [RSS Fulltext Proxy](https://github.com/Kombustor/rss-fulltext-proxy) - Mirrors RSS feeds to return the full content of the items, extracted from the website. `MIT` `NodeJS`
 - [RSS Merger](https://github.com/taophp/rss-merger) - PHP script which will take multiple RSS / Atom feeds as input and merge them into a single RSS feed. `GPL-2.0` `PHP`
 - [RSS-Bridge](https://github.com/sebsauvage/rss-bridge) - rss-bridge is a PHP project capable of generating ATOM feeds for websites which don't have one. `Public domain` `PHP`
-- [RSS2EMail](http://www.allthingsrss.com/rss2email/) - Fetches RSS/Atom-feeds and pushes new Content to any email-receiver, supports OPML. ([Source Code](https://github.com/wking/rss2email)) `GPL-2.0` `Python`
+- [RSS2EMail](https://github.com/wking/rss2email) - Fetches RSS/Atom-feeds and pushes new Content to any email-receiver, supports OPML. `GPL-2.0` `Python`
 - [Screaming Liquid Tiger](https://github.com/herrbischoff/screaming-liquid-tiger) - Simple script to automatically generate valid RSS and Atom feeds from a list of media files in the same folder. `MIT` `PHP`