feature: Add an option to enable Telegram to work behind a proxy. (#6125)

Co-authored-by: Frank Elsinga <frank@elsinga.de>

server/notification-providers/brevo.js

@@ -18,6 +18,7 @@ class Brevo extends NotificationProvider {
                     "api-key": notification.brevoApiKey,
                 },
             };
+            config = this.getAxiosConfigWithProxy(config);
 
             let to = [{ email: notification.brevoToEmail }];