[4.0] Pass proper arguments to the Response constructor

[xuxucode]

\GuzzleHttp\Psr7\Response::__construct 的签名:

    /**
     * @param int                                  $status  Status code
     * @param array                                $headers Response headers
     * @param string|null|resource|StreamInterface $body    Response body
     * @param string                               $version Protocol version
     * @param string|null                          $reason  Reason phrase (when empty a default will be used based on the status code)
     */
    public function __construct(
        $status = 200,
        array $headers = [],
        $body = null,
        $version = '1.1',
        $reason = null
    ) {

body 为第三个参数