add missing </h2>

 - Legacy-Id: 592

Author: Michael Lee

ietf/templates/iesg/ietf_doc.html

@@ -35,7 +35,7 @@
 {% endblock %}
 {% block content %}
 {% if is_recent %}
-<center><h2>Recent IESG Announcements</center>
+<center><h2>Recent IESG Announcements</h2></center>
 <blockquote>
 This page contains links to all IESG Protocol, Document, and Working Group Action announcements that have been sent within the past six months. Announcements that were sent prior to six month ago can be found in <a href="previous/">Previous Announcements</a>.<br>
 <br>