Fixes #11760: Remove mailing list links from readme and about pages

Links are dead now since Google blacklisted the group for massive spam,
which they could be of no help in resolving. We’ll have a new official
forum for discussions soon folks <3.

README.md

@@ -123,7 +123,6 @@ Keep track of development and community news.
 
 * Follow [@twbootstrap on Twitter](http://twitter.com/twbootstrap).
 * Read and subscribe to [The Official Bootstrap Blog](http://blog.getbootstrap.com).
-* Have a question that's not a feature request or bug report? [Ask on the mailing list.](http://groups.google.com/group/twitter-bootstrap)
 * Chat with fellow Bootstrappers in IRC. On the `irc.freenode.net` server, in the `##twitter-bootstrap` channel.
 
 

about.html

@@ -69,7 +69,6 @@ <h1 id="community">Community</h1>
   <p class="lead">Stay up to date on the development of Bootstrap and reach out to the community with these helpful resources.</p>
   <ul>
     <li>Read and subscribe to <a href="http://blog.getbootstrap.com/">The Official Bootstrap Blog</a>.</li>
-    <li>Have a question that's not a feature request or bug report? <a href="http://groups.google.com/group/twitter-bootstrap">Ask on the mailing list.</a></li>
     <li>Chat with fellow Bootstrappers using IRC in the <code>irc.freenode.net</code> server, in the <a href="irc://irc.freenode.net/#twitter-bootstrap">##twitter-bootstrap channel</a>.</li>
     <li>Find inspiring examples of people building with Bootstrap at the <a href="http://expo.getbootstrap.com">Bootstrap Expo</a>.</li>
   </ul>