Description of problem:
If comment the parameter "rhn_pool", heat stack can't created.(passing additional repos by "extra_repository_urls" instead of using RHN account)

Version-Release number of selected component (if applicable):
openshift-on-openstack v0.9.1

How reproducible:
100%

Steps to Reproduce:
1.#cat ocp.yaml
parameters:
<--snip-->
  #rhn_username: "Your RHN Username"
  #rhn_password: "Your RHN Password"
  #sat6_hostname: ""
  #sat6_organization: ""
  #sat6_activationkey: ""
  #rhn_pool: ''
<--snip-->

2.#heat stack-create ghuang-test1 -t 10800 -e ocp.yaml -P extra_repository_urls="xxx.redhat.com/rhel.repo" -f /usr/share/openshift-on-openstack/openshift.yaml
WARNING (shell) "heat stack-create" is deprecated, please use "openstack stack create" instead
ERROR: The Parameter (rhn_pool) was not provided.

3.After uncomment "rhn_pool", heat stack created successfully, actually rhn_pool would not be used as I had passed additional repos by "extra_repository_urls".

Actual results:


Expected results:
Heat stack should be created successfully if "rhn_pool" is not defined

Additional info: