Multiple Services 在启用 Connection Multiplexing 的情况下不能正常工作

[aaronjheng]

Describe the bug

Multiple Services 在启用 Connection Multiplexing 的情况下不能正常工作

To Reproduce

Steps to reproduce the behavior:

1. 克隆 https://github.com/cloudwego/kitex
2. 修改 protobuf_multi_service
   1. Client 增加 client.WithMuxConnection(1) 选项
   2. Server 增加 server.WithMuxTransport() 选项
3. 运行 Server
4. 运行 Client

Expected behavior

Client程序能正常输出

Screenshots

Client 报错

Server 报错

Kitex version:

0.9.0

Environment:

The output of go env.

Additional context