Tell Twisted to keep producing data after connection upgrade

daphne/http_protocol.py

@@ -110,6 +110,10 @@ class WebRequest(http.Request):
                     logger.debug("Connection %s did not get successful WS handshake.", self.reply_channel)
                 del self.factory.reply_protocols[self.reply_channel]
                 self.reply_channel = None
+
+                # Resume the producer so we keep getting data
+                self.channel.resumeProducing()
+
             # Boring old HTTP.
             else:
                 # Sanitize and decode headers, potentially extracting root path