Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -6,4 +6,4 @@ When a problem occurs, then always for a reason! What you want to do in such a c
 4. Read the documentation of the troubled service and search it's bugtracker for your problem.
 5. Search our [issues](https://github.com/mailcow/mailcow-dockerized/issues) for your problem.
 6. [Create an issue](https://github.com/mailcow/mailcow-dockerized/issues) over at our GitHub repository if you think your problem might be a bug or a missing feature you badly need. But please make sure, that you include **all the logs** and a full description to your problem.
-8. Connect to IRC ([chat.freenode.net](https://webchat.freenode.net/)) and join our IRC channel [#mailcow](irc://chat.freenode.net:6667/mailcow).
+8. Connect to IRC ([chat.freenode.net](https://webchat.freenode.net/)) and join our IRC channel #mailcow.