Call to process_one(wait=False) raises exception when there is nothing to process

[Kirill888]

I think code here is trying to catch wrong exception:

ipykernel/ipykernel/kernelbase.py

Lines 442 to 445 in 3c6037f

	try:
	t, dispatch, args = self.msg_queue.get_nowait()
	except asyncio.QueueEmpty:
	return None

My guess is that tornado.queues.QueueEmpty was the intended exception, and not asyncio.QueueEmpty

[blink1073]

Fixed in #817