Fixes Redis link on homepage. Closes #416

docs/homepage/index.html

@@ -79,7 +79,7 @@ pageTracker._trackPageview();
         >operate with other languages</a> using webhooks.</p>
 
     <p>The recommended message broker is <a href="http://rabbitmq.com/">RabbitMQ</a>,
-        but limited support for <a href="http://redisdb.com/">Redis</a>, <a
+        but limited support for <a href="http://redis.io/">Redis</a>, <a
             href="http://kr.github.com/beanstalkd/">Beanstalk</a>, <a
             href="http://www.mongodb.org/">MongoDB</a>, <a
             href="http://couchdb.apache.org/">CouchDB</a>, and databases