Update release date for 1.10.6

Author: ywarnier

documentation/changelog.html

@@ -49,7 +49,7 @@ <h1>Chamilo&nbsp;Changelog</h1>
 
     <a name="1.10.6"></a>
 
-    <h1>Chamilo 1.10.6 - Zacatecas, 20 of May 2016</h1>
+    <h1>Chamilo 1.10.6 - Zacatecas, 23rd of May 2016</h1>
     <h3>Release notes - summary</h3>
     <p>Chamilo 1.10.6 is a minor, bugfix release of the 1.10.x branch, with a few new features and bugfixes on top of 1.10.4.</p>
     <h3>Release name</h3>