CS-Cart で Warning: The secure connection check has failed. Check HTTPS settings in config.php file and make sure that SSL certificate is installed on your server. エラーが出たときの対処法

Secure connection fails より
nginx上のCS-Cart で

Warning: The secure connection check has failed. Check HTTPS settings in config.php file and make sure that SSL certificate is installed on your server.

というエラーが出たときは、prepare.php の

if (isset($_SERVER['HTTPS']) && ($_SERVER['HTTPS'] == 'on' || $_SERVER['HTTPS'] == '1')) {
        define('HTTPS', true);
の後に

} elseif ($_SERVER['SERVER_PORT']=='443') {
        define('HTTPS', true);
を追加する