Re-enable Windows support

It works well enough now with the recent fixes and a modern Python.

websockify/websockifyserver.py

@@ -40,9 +40,6 @@ for mod, msg in [('ssl', 'TLS/SSL/wss is disabled'),
 if sys.platform == 'win32':
     # make sockets pickle-able/inheritable
     import multiprocessing.reduction
-    # the multiprocesssing module behaves much differently on Windows,
-    # and we have yet to fix all the bugs
-    sys.exit("Windows is not supported at this time")
 
 from websockify.websocket import WebSocket, WebSocketWantReadError, WebSocketWantWriteError
 from websockify.websocketserver import WebSocketRequestHandlerMixIn