Update WG IRC channel link.

Author: gkellogg

index.html

@@ -270,7 +270,7 @@ <h2>Contributing</h2>
       <li>Technical discussion typically occurs on the working group mailing list:
         <a href="https://lists.w3.org/Archives/Public/public-json-ld-wg/">[email protected]</a></li>
 
-      <li>The working group uses <em>#json-ld</em>
+      <li>The working group uses <a href="http://irc.w3.org/?channels=json-ld">#json-ld</a>
         IRC channel is available for real-time discussion on <a href="http://irc.w3.org">irc.w3.org</a>.</li>
 
       <li>The <a href="https://webchat.freenode.net/?channels=json-ld">#json-ld</a>