Heat stack using OS::Designate::Record cannot be deleted if Domain has been deleted

[Anatolii Neliubin]

Steps to reproduce:
1. Create a Designate Domain:
# openstack zone create --email <email address hidden> example.com.
2. Make a new Heat stack using records in that Designate domain using following template:
# cat stack_creating_record.yaml
heat_template_version: 2015-10-15
description: Basic Cluster Test
parameters:
  domain_name:
    type: string
    default: "example.com."
resources:
  record_test:
    type: OS::Designate::Record
    properties:
      name: { list_join: [".",[testrecord, {get_param: domain_name }]]}
      type: A
      data: 1.2.3.4
      domain: { get_param: domain_name }
      ttl: 900
# openstack stack create -t stack_creating_record.yaml stack_creating_record
3. Delete a Designate zone created before:
# openstack zone delete example.com.
4. delete Heat stack created earlier:
# openstack stack delete stack_creating_record
5. Heat stack cannot be deleted:
openstack stack show stack_creating_record -c stack_status_reason
+---------------------+------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+---------------------+------------------------------------------------------------------------------------------------------------------------+
| stack_status_reason | Resource DELETE failed: EntityNotFound: resources.record_test: The Designate Domain (example.com.) could not be found. |
+---------------------+------------------------------------------------------------------------------------------------------------------------+

Workaround: To recreate Domain and then to delete the stack.