Updated WorkingPaperImExporter to implement updated interface.

sci-publications/src/main/java/org/scientificcms/publications/WorkingPaperImExporter.java

@@ -26,4 +26,12 @@ public class WorkingPaperImExporter
         addRequiredEntities(Set.of(Organization.class));
     }
 
+    @Override
+    protected void updateExistingUnPublished(
+        final WorkingPaper existingPublication,
+        final WorkingPaper withImportedPublication
+    ) {
+        // Nothing to update in WorkingPaper
+    }
+
 }