patch: serial op failed on windows (in boost::asio)

see: https://github.com/chriskohlhoff/asio/issues/717

server/thirdparty/boost/boost/asio/detail/impl/win_iocp_serial_port_service.ipp

@@ -84,7 +84,7 @@ boost::system::error_code win_iocp_serial_port_service::open(
   dcb.fBinary = TRUE; // Win32 only supports binary mode.
   dcb.fNull = FALSE; // Do not ignore NULL characters.
   dcb.fAbortOnError = FALSE; // Ignore serial framing errors.
-  dcb.BaudRate = 0; // 0 baud by default
+  dcb.BaudRate = CBR_9600; // 9600 baud by default
   dcb.ByteSize = 8; // 8 bit bytes
   dcb.fOutxCtsFlow = FALSE; // No flow control
   dcb.fOutxDsrFlow = FALSE;