沙箱模式的Notify总是出错：Invalid request payloads.

[exsystem]

我用的环境

PHP 版本：7.0
overtrue/wechat 版本：3.3.20
是否使用了框架？框架名称：XFramework

问题及现象

公众号支付（JSAPI）沙箱模式的Notify总是提示：“Invalid request payloads.”，然而正式模式却一切正常。

发起支付：

$app     = $this->getEasyWechatApp();
        $payment = $app->payment;
        $payment->sandboxMode($this->FConfig->GetBoolean('Application.Wechat.payment.sandbox_mode')); //如果是false一切正常，true则失败
        try {
            $attributes = [
                'trade_type'   => 'JSAPI',
                'body'         => '****',
                'detail'       => TUuid::ToString($mOrderId, ''),
                'out_trade_no' => TUuid::ToString($mOrderId, ''),
                'total_fee'    => 1, //$mTotalFee, //如果是沙箱模式，我这里写的是101，对应微信的测试的case
                'openid'       => $this->getWechatOpenId(),
            ];

            $order  = new Order($attributes);
            $result = $payment->prepare($order);
            if ($result['return_code'] == 'SUCCESS' && $result['result_code'] == 'SUCCESS') {
                $prepayId = $result['prepay_id'];
                $config   = $payment->configForJSSDKPayment($prepayId);
            }
        }
        catch (EInvalidParameter $e) {
            //NOP
        }
        return $config;

NotifyHandler：

try {
            $mModel = new TOrderModel($this->FConfig, '');
            $payment = $this->getEasyWechatApp()->payment;
            $payment->sandboxMode($this->FConfig->GetBoolean('Application.Wechat.payment.sandbox_mode'));
            $response = $payment->handleNotify(function ($notify, $successful) use ($mModel) {
                TLogger::LogVariable($notify);
                $order = $mModel->GetOrder(TUuid::FromString($notify['out_trade_no']));
                if ($order === null) {
                    return 'Order not exist.';
                }
                if ($order->OrderStatus == TOrderStatus::ePaid()) {
                    return true;
                }
                if ($successful) {
                    $order->OrderStatus = TOrderStatus::ePaid();
                    TLogger::LogMessage('PAY SUCC');
                    TLogger::LogMessage($notify['total_fee']);
                }
                $mModel->UpdateOrderStatus($order->OrderId, $order->OrderStatus);
                return true;
            });
            TLogger::LogMessage('response = ');
            TLogger::LogMessage($response->getContent());
            $response->send();
        }
        catch (\Exception $e) {
            TLogger::LogMessage($e->getMessage());
        }
        finally {
            Framework::Free($mModel);
        }

[mingyoung]

PR #1036