remove symphony - source code gone, website changed owner

README.md

@@ -457,7 +457,6 @@ _[SIP](https://en.wikipedia.org/wiki/Session_Initiation_Protocol)/[IPBX](https:/
 - [Scoold](https://scoold.com) - Stack Overflow in a JAR. An enterprise-ready Q&A platform with full-text search, SAML, LDAP integration and social login support. ([Demo](https://live.scoold.com), [Source Code](https://github.com/Erudika/scoold)) `Apache-2.0` `Java`
 - [Simple Machines Forum](https://www.simplemachines.org/) - Free, professional grade software package that allows you to set up your own online community within minutes. ([Source Code](https://github.com/SimpleMachines/SMF2.1)) `BSD-3-Clause` `PHP`
 - [Socialhome](https://socialhome.network) - Federated and decentralized profile builder and social network engine. ([Demo](https://socialhome.network/), [Source Code](https://github.com/jaywink/socialhome)) `AGPL-3.0` `Python`
-- [Symphony](https://hacpai.com/) - Modern community (forum/SNS/blog) platform written in Java. ([Source Code](https://github.com/b3log/symphony)) `GPL-3.0` `Java`
 - [Talkyard](https://www.talkyard.io/) - Create a community, where your users can suggest ideas and get questions answered. And have friendly open-ended discussions and chat (Slack/StackOverflow/Discourse/Reddit/Disqus hybrid). ([Demo](https://www.talkyard.io/forum/latest), [Source Code](https://github.com/debiki/talkyard)) `AGPL-3.0` `Scala`
 - [Tokumei](https://tokumei.co/) - Anonymous microblogging platform. ([Source Code](https://gitlab.com/tokumei/tokumei)) `ISC` `rc`
 - [Thredded](https://thredded.org) - Forums, feature-rich and simple. ([Demo](https://thredded.org/thredded), [Source Code](https://github.com/thredded/thredded)) `MIT` `Ruby`