Fix bulk-delete rows for import/export batch

per changes in SQLAlchemy 1.4

tailbone/views/batch/importer.py

@@ -277,7 +277,7 @@ class ImporterBatchView(BatchMasterView):
         query = self.get_effective_row_data(sort=False)
         batch.rowcount -= query.count()
         delete_query = self.current_row_table.delete().where(self.current_row_table.c.uuid.in_([row.uuid for row in query]))
-        delete_query.execute()
+        self.Session.bind.execute(delete_query)
         return self.redirect(self.get_action_url('view', batch))
 
     def get_row_xlsx_fields(self):