SantaGUI: ensure bundle listeners are invalidated (#373)
SantaGUI: ensure bundle listeners are invalidated (#373)

When setting a new bundle service listener, it was possible for an existing listener to be replaced without invalidating it first. This can cause crashes if a process somehow tries to connect to that listener later on.
google/santa,russellhancox/santa,russellhancox/santa,google/santa,tburgin/santa,russellhancox/santa,tburgin/santa,google/santa,tburgin/santa