[i573] restore cloning Datafield ()

Merging branch 'i573'  into 'main'.

See merge request !1592

GUI/Model/Job/JobItem.cpp

@@ -384,7 +384,7 @@ void JobItem::cropRealData()
     // Adjust real data to the size of region of interest
     IntensityDataItem* intensityItem = realItem()->intensityDataItem();
 
-    const Datafield* origData = intensityItem->c_field();
+    std::unique_ptr<Datafield> origData(intensityItem->c_field()->clone());
 
     const auto converter = iiI->createCoordSystem();
     ASSERT(converter);