Update ABOUT.html to fix copyright dates.

static/plugin_dbui/ABOUT.html

@@ -39,4 +39,4 @@
 <h2 id="changelog">Changelog</h2>
 <p>Consult the <a href="CHANGELOG">Changelog</a> page for fixes and enhancements of each version.</p>
 <h2 id="license">License</h2>
-<p>Copyright Renaud Le Gac, 2009-2016. Distributed under the terms of the <a href="http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.html">CECIL</a> license, <code>plugin_dbui</code> is free and open source software.</p>
+<p>Copyright Renaud Le Gac, 2009-2019. Distributed under the terms of the <a href="http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.html">CECIL</a> license, <code>plugin_dbui</code> is free and open source software.</p>