自动播放下一个语音, 如何判断该语音是否读过，是要本地做消息缓存么。自动缓存读过的Messageid

[FelixVarius]

Base Info for this issue

1. ChatKit Version：0.7.17
2. App-ID: XX
3. Language：Objective-C
4. iOS System Version：iOS10
5. Prototype（是否是真机）：YES
6. Issue Type：Crash、Bug、Enhancement（希望能支持一个新需求）、Q-A

1. How to repeat the problem.

2. Please help me in this way.

3. Here is a Demo.

4. Here is my Debug log