Merge pull request #3449 from pavlin-policar/feature-statistics-fix

[FIX] OWFeatureStatistics: Don't attempt to sort when no data on input

Orange/widgets/data/owfeaturestatistics.py

@@ -807,7 +807,7 @@ def __restore_selection(self):
     def __restore_sorting(self):
         """Restore the sort column and order from saved settings."""
         sort_column, sort_order = self.sorting
-        if sort_column < self.model.columnCount():
+        if self.data is not None and sort_column < self.model.columnCount():
             self.model.sort(sort_column, sort_order)
             self.table_view.horizontalHeader().setSortIndicator(sort_column, sort_order)