Fix enormous bug in subscribe(EventSubscriber)

Thanks to Gabriel Selzer for pointing it out.

src/main/java/org/scijava/event/DefaultEventService.java

@@ -140,7 +140,7 @@ public List<EventSubscriber<?>> subscribe(final Object o) {
 
 	@Override
 	public void subscribe(final EventSubscriber<?> subscriber) {
-		eventBus.subscribe(subscriber.getClass(), subscriber);
+		eventBus.subscribe(subscriber.getEventClass(), subscriber);
 	}
 
 	@Override