Comment 1 for bug 1621625

It works on 9.1.
I see in heat.conf:
heat_waitcondition_server_url=http://172.16.0.3:8000/v1/waitcondition which is public url.
heat_waitcondition_server_url is used only in one place for generating ec2 signed url which you pass to cfn-signal, so I think it is safe to change it to public url. Also, OS::Heat::WaitConditionHandle works because it uses another signal transport with public url (by default).