Fixed it need 18mins timeout to shutdown socket when it lost network …

[G-MoYang]

…connection

[G-MoYang]

I am using SignalR library.
websocketpp is one port of vcpkg.
Envoriment: Raspberry pi， Raspbian GNU/Linux 11
Reprso Steps:

1. Setup connection with server by SignalR(websocket)
2. Disable network connection.
3. Call close() in ws_client_wspp.cpp
4. It send close frame to server.
5. It timeout by 10s close hanshake.
6. It not cancel socket successfully, so it keep wait. (handle_close_handshake_timeout()->terminate()->transport_con_type::async_shutdown()->handle_async_shutdown_timeout()->cancel_socket_checked()->socket_con_type::cancel_socket())