fixing a trivial HTML tag which is closed twice

Author: atombrella

docs_theme/base.html

@@ -136,7 +136,7 @@ <h3 id="myModalLabel">Documentation search</h3>
   </div> <!--/.wrapper -->
 
   <footer class="span12">
-    <p>Documentation built with <a href="http://www.mkdocs.org/">MkDocs</a>.</a>
+    <p>Documentation built with <a href="http://www.mkdocs.org/">MkDocs</a>.
     </p>
   </footer>