Fix linux build

mapeditor/mapview.cpp

@@ -362,8 +362,9 @@ void MapView::dragEnterEvent(QDragEnterEvent * event)
 	{
 		auto encodedData = event->mimeData()->data("application/vcmi.object");
 		QDataStream stream(&encodedData, QIODevice::ReadOnly);
-		QJsonObject data;
-		stream >> data;
+		QVariant vdata;
+		stream >> vdata;
+		auto data = vdata.toJsonObject();
 		if(!data.empty())
 		{
 			auto preview = data["preview"];

mapeditor/objectbrowser.cpp

@@ -108,7 +108,7 @@ QMimeData * ObjectBrowserProxyModel::mimeData(const QModelIndexList & indexes) c
 	if(!index.isValid())
 		return nullptr;
 	
-	auto text = standardModel->itemFromIndex(mapToSource(index))->data().toJsonObject();
+	auto text = standardModel->itemFromIndex(mapToSource(index))->data();
 	stream << text;
 
 	QMimeData * mimeData = new QMimeData;