Handle "type" key in dicts being part of object state attrs

i.e. the confusion of the state file deserializator with e.g. `"type":32` on startup.
That would unexpectedly restore (the now ignored) null (not `{"type":32}`) as there's no type "32".

refs #8186

lib/notification/notificationcomponent.cpp

@@ -181,6 +181,9 @@ void NotificationComponent::NotificationTimerHandler()
 				ObjectLock olock(unstashedNotifications);
 
 				for (Dictionary::Ptr unstashedNotification : unstashedNotifications) {
+					if (!unstashedNotification)
+						continue;
+
 					try {
 						Log(LogNotice, "NotificationComponent")
 							<< "Attempting to send stashed notification '" << notificationName << "'.";