Contao\Config::remove PHP Method

    public static function remove($strKey)
    {
        $objConfig = static::getInstance();
        if (strncmp($strKey, '$GLOBALS', 8) !== 0) {
            $strKey = "\$GLOBALS['TL_CONFIG']['{$strKey}']";
        }
        $objConfig->delete($strKey);
    }

 /**
  * Permanently removes a configuration value.
  *
  * @param string $key The short key or full variable name
  */
 public function remove($key)
 {
     Config::remove($key);
 }