Handle prefixed messages from the server

http2irc.py

@@ -303,6 +303,9 @@ class IRCClientProtocol(asyncio.Protocol):
 
 	def message_received(self, message):
 		logging.info(f'Message received: {message!r}')
+		if message.startswith(b':'):
+			# Prefixed message, extract command + parameters (the prefix cannot contain a space)
+			message = message.split(b' ', 1)[1]
 		if message.startswith(b'PING '):
 			self.send(b'PONG ' + message[5:])
 		elif message.startswith(b'PONG '):