北方地区上传报错，incorrect zone, please use up-z1.qiniu.com

 /**
     * Qiniu constructor.
     * @param $accessKey
     * @param $secretKey
     * @param $domain
     * @param string $bucket
     * @param string $zone 默认华南机房
     */
    function __construct($accessKey, $secretKey, $domain, $bucket, $zone = 'south_china')
    {
        $this->accessKey = $accessKey;
        $this->secretKey = $secretKey;
        $this->domain = $domain;
        $this->bucket = $bucket;

        $config = $this->zoneConfig($zone);

        $this->up_host = $config['up'][0];  //读取第一个可用线路


    }

 protected function zoneConfig($key = null)
    {
        $arr = [
            //华东
            'east_china' => [
                'up' => array("up.qiniup.com", 'up-nb.qiniup.com', 'up-xs.qiniup.com'),
            ],
            //华北
            'north_china' => [
                'up' => array('up-z1.qiniup.com'),
            ],
            //华南机房
            'south_china' => [
                'up' => array('up-z2.qiniup.com', 'up-gz.qiniup.com', 'up-fs.qiniup.com'),
            ],
            //北美机房
            'north_america' => [
                'up' => array('up-na0.qiniup.com'),
            ]
        ];
        if ($key !== null) {
            if (isset($arr[$key])) {
                return $arr[$key];
            } else {
                throw new \Exception('区域不存在');
            }
        }
        return $arr;
    }

$qiniu = new Qiniu(Product::AK, Product::SK, Product::DOMAIN, Product::BUCKET,'north_china');

 //上传图片
    public function upload()
    {
        if ($_FILES['Product']['error']['cover'] > 0) {
            return false;
        }

        $qiniu = new Qiniu(Product::AK, Product::SK, Product::DOMAIN, Product::BUCKET,'north_china');
        $key = uniqid();
        $qiniu->uploadFile($_FILES['Product']['tmp_name']['cover'], $key);
        $cover = $qiniu->getLink($key);
        $pics = [];
        foreach ($_FILES['Product']['tmp_name']['pics'] as $k => $file) {
            if ($_FILES['Product']['error']['pics'][$k] > 0) {
                continue;
            }
            $key = uniqid();
            $qiniu->uploadFile($file, $key);
            $pics[$key] = $qiniu->getLink($key);
        }

        return ['cover' => $cover, 'pics' => json_encode($pics)];
    }