MDL-83692 factor_sms: add notification for SMS gateway restriction

admin/tool/mfa/factor/sms/lang/en/factor_sms.php

@@ -55,7 +55,7 @@ $string['settings:gateway_help'] = 'The SMS provider you wish to send messages v
 $string['settings:heading'] = 'Users will receive an SMS with 6-digit code during login, which they must enter to complete the login process.
 
 Users will need to register their mobile phone number first.';
-$string['settings:setupdesc'] = '<br><br>To use SMS as an authentication factor, you first need to <a href="{$a}">set up an SMS gateway</a>.';
+$string['settings:setupdesc'] = 'To use SMS as an authentication factor, you first need to <a href="{$a}">set up an SMS gateway</a>.';
 $string['settings:smsgateway'] = 'SMS gateway';
 $string['settings:smsgateway_help'] = 'Select a gateway from the list, or <a href="{$a}">create a new gateway</a>.';
 $string['setupfactor'] = 'Set up SMS';

admin/tool/mfa/factor/sms/settings.php

@@ -105,16 +105,10 @@ if ($ADMIN->fulltree) {
         );
         $settings->hide_if('factor_sms/duration', 'factor_sms/enabled');
     } else {
-        $settings->add(
-            new admin_setting_description(
-                'factor_sms/setupdesc',
-                '',
-                new lang_string(
-                    'settings:setupdesc',
-                    'factor_sms',
-                    $smsconfigureurl,
-                ),
-            ),
+        $notify = new \core\output\notification(
+            get_string('settings:setupdesc', 'factor_sms', $smsconfigureurl),
+            \core\output\notification::NOTIFY_WARNING
         );
+        $settings->add(new admin_setting_heading('factor_sms/setupdesc', '', $OUTPUT->render($notify)));
     }
 }