fix cyrus-impad source code link syntax

- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/2266

README.md

@@ -397,7 +397,7 @@ Simple deployment of [E-mail](https://en.wikipedia.org/wiki/Email) servers, e.g.
 
 [Mail Delivery Agents](https://en.wikipedia.org/wiki/Message_delivery_agent) (MDAs) - [IMAP](https://en.wikipedia.org/wiki/Internet_Message_Access_Protocol)/[POP3](https://en.wikipedia.org/wiki/Post_Office_Protocol) server software.
 
-- [Cyrus IMAP](https://www.cyrusimap.org/) - Email (IMAP/POP3), contacts and calendar server. ([Source Code](https://github.com/cyrusimap/cyrus-imapd )) `BSD-3-Clause-Attribution` `C`
+- [Cyrus IMAP](https://www.cyrusimap.org/) - Email (IMAP/POP3), contacts and calendar server. ([Source Code](https://github.com/cyrusimap/cyrus-imapd)) `BSD-3-Clause-Attribution` `C`
 - [Dovecot](https://www.dovecot.org/) - IMAP and POP3 server written primarily with security in mind. ([Source Code](https://github.com/dovecot/core)) `MIT/LGPL-2.1` `C`
 - [MailForm](https://github.com/Feuerhamster/mailform) - Lightweight self-hosted open source alternative to Formspree and SendGrid. `Apache-2.0` `Nodejs`
 - [Piler](https://www.mailpiler.org/wiki/start) - Feature-rich open source email archiving solution. ([Source Code](https://bitbucket.org/jsuto/piler)) `GPL-3.0` `C`