Fixes nozzle deleting and adds some safety to nozzle toggling

Fixes #4175 

~~The "noz == null" check takes some time to work if the nozzle has been qdel'd. If there is some method to call that handles checking if an object has been qdel'd I'll add that into the conditional.~~

For clarification, I tested by right clicking the object and Deleting it with admin verb.