Result channel sometimes includes bogus events

[rainest]

Testing in the course of writing Kong/kubernetes-ingress-controller#6131 found that the result channel sometimes gets phantom events with no content whatsoever.

I'm not entirely sure where these are coming from, as I couldn't find anything in the code section that sends to them that didn't at least set a static event action type string, and wasn't able to find any other paths somehow sending empty structs into it by watching the buffer in a debugger.

#119 fixes the issue I was seeing where no real results were being sent, but I was still seeing some empty ones come through also.

It was easy enough to just discard these in KIC#6131 as a workaround, and it's quite possible that's sufficient given that we have no other expected consumers of the event channel unless we get around to carving out the deck legacy logger in #22.