OVDB-82: Added note re Houdini support to news item.

Signed-off-by: Peter Cucka <peter.cucka@dreamworks.com>

Author: pcucka

index.html

@@ -112,6 +112,8 @@ <h3>May 8, 2019</h3>
             </ul>
             <p>See the <a href="./documentation/doxygen/changes.html#v6_1_0_changes"
                target="_blank">release notes</a> for a complete list of changes.</p>
+            <p>Note that as of this release, Houdini versions 16.0 and older
+               are no longer supported.</p>
           </div>
 
           <div class="news_item">