removed duplicate key
removed duplicate key

In review of this role it was discovered that we had a duplicate
key within a task. While this is acceptable in Ansible as it will
just use the last key found in a given task it is wrong and should
be removed. In later version of Ansible (2.1.0) a warning is printed
stating something similar to the following:

   [WARNING]: While constructing a mapping from xxx.yml, line xx,
     column xx, found a duplicate dict key (changed_when).  Using
     last defined value only. [WARNING]: While constructing a mapping
     from xxx.yml, line xx, column xx, found a duplicate dict key
     (changed_when).  Using last defined value only.

This chage cleans up the role by removing the duplication.

Change-Id: I164facafe810a47d0c922cc59687ba4f45da959a

BjoernT/openstack-ansible,major/os-ansible-deployment,cfarquhar/openstack-ansible,mancdaz/openstack-ansible,openstack/openstack-ansible,Logan2211/openstack-ansible,cfarquhar/openstack-ansible,robb-romans/openstack-ansible,BjoernT/os-ansible-deployment,BjoernT/os-ansible-deployment,yanyao/openstack-ansible,os-cloud/os-ansible-deployment,mrda/openstack-ansible,yanyao/newton,yanyao/newton,os-cloud/os-ansible-deployment,cloudnull/os-ansible-deployment,weezer/openstack-ansible,bunchc/openstack-ansible,yanyao/openstack-ansible,stackforge/os-ansible-deployment,robb-romans/openstack-ansible,stackforge/os-ansible-deployment,mancdaz/openstack-ansible,cloudnull/os-ansible-deployment,major/openstack-ansible,major/openstack-ansible,weezer/openstack-ansible,BjoernT/os-ansible-deployment,openstack/openstack-ansible,mrda/openstack-ansible,bunchc/openstack-ansible,BjoernT/openstack-ansible,mrda/openstack-ansible,Logan2211/openstack-ansible,major/os-ansible-deployment