Replace [] with "[]" in permission setup ajax calls

git-svn-id: http://xe-core.googlecode.com/svn/branches/maserati@11744 201d5d3c-b55e-5fd7-737f-ddc643e51545

modules/menu/tpl/sitemap.html

@@ -2539,6 +2539,8 @@ jQuery(function($){
 			}
 		}
 		
+		// Output of $.param function used in exec_json does not have a representation for an empty array. So, use "[]" (string) instead.
+		if(vValue.length === 0) vValue = "[]";
 		return vValue;
 	}