Question about -s WEBSOCKET_SUBPROTOCOL=null and -s PROXY_POSIX_SOCKETS=1

Hello everyone

I have set -s WEBSOCKET_SUBPROTOCOL=null without call emscripten_init_websocket_to_posix_socket_bridge function
the server side works fine(websocketpp)

then I have set -s PROXY_POSIX_SOCKETS=1,and call emscripten_init_websocket_to_posix_socket_bridge ,receved size is not what I expected,is it ignore handshake=null while set -s PROXY_POSIX_SOCKETS=1?

the code link

[Server](https://github.com/fatmingwang/FM79979/blob/master/Src/FM79979Engine/EmptyProject/EngineTest/WebsocketServer.cpp#L233)
[Client](https://github.com/fatmingwang/FM79979/blob/master/Src/FM79979Engine/Core/Network/GameNetWork.cpp#L16)