Correct unit file name check for heat_api_cfn validation.
Correct unit file name check for heat_api_cfn validation.

The verification of the heat-api-cfn service running under
http, relies on checking the httpd control group tree
hierarchy. In this tree, the heat_api_cfn_wsgi service name
is trimmed, causing a validation error during upgrades.

Change-Id: Id1c932ab0ebb1e8b155e49b01c70e53e58c00214
Closes-Bug: #1780248

dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates