doc: remove bad link to irc info

Remove a link that no longer appears to point to information about
Node.js IRC channels.

PR-URL: nodejs#24967
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

README.md

@@ -50,8 +50,7 @@ If you didn't find an answer in the resources above, try these unofficial
 resources:
 
 * [Questions tagged 'node.js' on StackOverflow][]
-* [#node.js channel on chat.freenode.net][]. See <http://nodeirc.info/> for more
-  information.
+* [#node.js channel on chat.freenode.net][]
 * [Node.js Discord Community](https://discordapp.com/invite/v7rrPdE)
 * [Node.js Slack Community](https://node-js.slack.com/): Visit
   [nodeslackers.com](http://www.nodeslackers.com/) to register.