Fix mqtt items asserting on client instances

src/items/itemloadersource.cpp

@@ -26,6 +26,7 @@ void ItemLoaderSource::refresh()
 			request.type = ITEM_UPDATE_LOADED;
 			request.payload = newItem;
 			request.changes = ItemFieldChanges(true);
+			request.changes.value = false;
 			itemAddRequests.push_back(request);
 		}
 	}