Keep null refresolver from getting added to eventlistener for event refs

The special casing for `event` references was leaving a null resolver in `EventListeners`, which trips up the code to remove event listeners in `unbind`.

Fixes #1438
do you think we should leave it? or can we remove it? 

It reads like an intentionally swallowed error. So if you think it should stay, we should at least add a comment IMO