Add 2.11.7 announcement.

Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

Author: igsilya

_includes/side-widgets.html

@@ -4,6 +4,9 @@
   </div>
   <div class="widget-body">
     <ul>
+      <li>
+        <a href=https://mail.openvswitch.org/pipermail/ovs-announce/2021-March/000274.html>Mar 05 2021: Open vSwitch 2.11.7 Available</a>
+      </li>
       <li>
         <a href=https://mail.openvswitch.org/pipermail/ovs-announce/2021-February/000273.html>Feb 15 2021: Open vSwitch 2.15.0 Available</a>
       </li>
@@ -67,9 +70,6 @@
       <li>
         <a href=https://mail.openvswitch.org/pipermail/ovs-announce/2017-September/000240.html>Sep 05 2017: Open vSwitch 2.8.0 Available</a>
       </li>
-      <li>
-        <a href=https://mail.openvswitch.org/pipermail/ovs-announce/2017-July/000239.html>Jul 18 2017: Open vSwitch 2.7.2 and 2.5.3 Available</a>
-      </li>
     </ul>
   </div>
 </div>