Fix wrapper class bug

The class for the wrapper section is stored in $types['wrapper_class'], not $types['class']

include/admin/admin_menu_new.php

@@ -1959,7 +1959,7 @@ function CreateNew(){
 				//wrapper section
 				$section							= gp_edit::DefaultContent('wrapper_section');
 				$section['contains_sections']		= count($types['types']);
-				$section['attributes']['class']		= $types['class'];
+				$section['attributes']['class']		= $types['wrapper_class'];
 				$content[]							= $section;