cleanup JobItem

GUI/Model/Job/JobItem.cpp

@@ -334,10 +334,10 @@ void JobItem::copyDatafileItemIntoJob(const DatafileItem* srcDatafileItem)
         m_realItem->data1DItem()->setRealPlotStyle();
 
         // coords of loaded data --> instrumental --> representation coords
-        const auto old = m_realItem->data1DItem()->c_field();
+        const Datafield* old = m_realItem->data1DItem()->c_field();
         Frame frame = instrumentItem()->makeFrame();
-        auto newDatafield = Datafield(frame.clone(), old->flatVector(), old->errorSigmas());
-        m_realItem->data1DItem()->setDatafield(newDatafield);
+        m_realItem->data1DItem()->setDatafield(
+            {frame.clone(), old->flatVector(), old->errorSigmas()});
     }
 }