ios app切到后台，获取不到推送的内容，不进入JPushModule.addReceiveNotificationListener方法

你的运行环境

• 插件版本:
• react-native 版本："0.59.5"
  "jcore-react-native": "^1.3.2",
  "jpush-react-native": "^2.5.3",

期望效果

ios app切到后台，能获取到推送的内容

实际效果

ios app切到后台，获取不到推送的内容，不进入JPushModule.addReceiveNotificationListener方法

重现步骤

1. app切到后台
2. 发送推送
3. 不进入JPushModule.addReceiveNotificationListener方法
   4.app在前台是，是可以进入JPushModule.addReceiveNotificationListener方法

Debug logs

包括 Android 或 iOS 的日志：

`JPushModule.setupPush();

        JPushModule.setBadge(0, success => {})

        //接收到通知
        this.receiveNotificationListener = map => {
            console.log('addReceiveNotificationListener:'+JSON.stringify(map));
        }
        JPushModule.addReceiveNotificationListener(this.receiveNotificationListener);`

Start by reproducing the iOS background case with React Native 0.59.5, jcore-react-native 1.3.2, and jpush-react-native 2.5.3. Read the integration around JPushModule.addReceiveNotificationListener and compare it with the foreground behavior; the issue is done when background notifications reach the listener with their content.