use config system.server_role and deprecate 'UNO'

include/widgets.php

@@ -595,7 +595,7 @@ function widget_settings_menu($arr) {
 	}
 
 	// IF can go away when UNO export and import is fully functional
-	if(! UNO) {
+	if(get_config('system','server_role') !== 'basic') {
 		$tabs[] =	array(
 			'label' => t('Export channel'),
 			'url' => z_root() . '/uexport',
@@ -609,7 +609,7 @@ function widget_settings_menu($arr) {
 		'selected' => ((argv(1) === 'oauth') ? 'active' : ''),
 	);
 
-	if(! UNO) {
+	if(get_config('system','server_role') !== 'basic') {
 		$tabs[] =	array(
 			'label' => t('Guest Access Tokens'),
 			'url' => z_root() . '/settings/tokens',