Use more pythonic logic

leasing/serializers/rent.py

@@ -612,7 +612,7 @@ def validate_override_receivable_type_value(
             # rent_data before later validations also during the update flow.
             # Try get ID from the rent instance, which is present if an existing
             # rent is being updated.
-            rent_id = self.instance.id if self.instance else None
+            rent_id = getattr(self.instance, "id", None)
 
         if rent_id is not None:
             self.full_validate_override_receivable_type(