Use 'today' as fallback date for ordering worksheet

tailbone/views/purchasing/ordering.py

@@ -170,8 +170,12 @@ class OrderingBatchView(PurchasingBatchView):
         history = list(reversed(history))
 
         title = self.get_instance_title(batch)
+        order_date = batch.date_ordered
+        if not order_date:
+            order_date = localtime(self.rattail_config).date()
         return self.render_to_response('worksheet', {
             'batch': batch,
+            'order_date': order_date,
             'instance': batch,
             'instance_title': title,
             'instance_url': self.get_action_url('view', batch),