Use is_admin() for admin check

interface/web/dns/form/dns_txt.tform.php

@@ -170,7 +170,7 @@ $form["tabs"]['dns'] = array (
 	)
 );
 
-if($_SESSION["s"]["user"]["typ"] == 'admin') {
+if($app->auth->is_admin()) {
 	unset($form["tabs"]['dns']['fields']['data']['validators']);
 	$form["tabs"]['dns']['fields']['data']['validators'][0]['type'] = 'NOTEMPTY';
 	$form["tabs"]['dns']['fields']['data']['validators'][0]['errmsg'] = 'data_error_empty';