stops redirect on login page

backend/config/application.php

@@ -23,6 +23,16 @@ if (file_exists($env_config)) {
     require_once $env_config;
 }
 
+/**
+ * Stops redirect loop on login page
+ */
+define('FORCE_SSL_ADMIN', true);
+// in some setups HTTP_X_FORWARDED_PROTO might contain 
+// a comma-separated list e.g. http,https
+// so check for https existence
+if (strpos($_SERVER['HTTP_X_FORWARDED_PROTO'], 'https') !== false)
+       $_SERVER['HTTPS']='on';
+
 /**
  * URLs
  */