Updating current version number.

Author: tomasguisasola

doc/us/index.html

@@ -67,7 +67,7 @@ <h2><a name="overview"></a>Overview</h2>
 <h2><a name="status"></a>Status</h2>
 
 <p>
-LuaSQL version 2.3.5 (for Lua 5.X) is now available for <a href="#download">download</a>.
+LuaSQL version 2.4.0 (for Lua 5.X) is now available for <a href="#download">download</a>.
 For more details on the features list please check the product
 <a href="history.html">history</a>.
 </p>