None input when use fileno with UDP

[5aaee9]

Hi, I was try use pysocks in shadowsocks-server (run socket server in TCP and UDP), but I was noticed that the UDP is not get client requests information. It use socket and select.select to watch the socket event

ref: Eventloop

It never get the UDP input data (The UDP socket fileno is never completion) It's works when I remove pysocks' monkeypatch