wsgi: make sure keystone service is stopped before starting httpd

When running Keystone in WSGI, we want to make sure Keystone service
(eventlet process) is stopped before starting Apache, otherwise it could
lead to binding issue.

Change-Id: I8b6b0e4900bb64f3878033f96bb24abc07f3646b

manifests/init.pp

@@ -925,6 +925,7 @@
       validate     => false,
     }
     $service_name_real = $::apache::params::service_name
+    Service['keystone'] ->  Service[$service_name_real]
   } else {
     fail('Invalid service_name. Either keystone/openstack-keystone for running as a standalone service, or httpd for being run by a httpd server')
   }

spec/classes/keystone_spec.rb

@@ -275,6 +275,7 @@
       'enable'          => false,
       'validate'        => false
     )}
+    it { is_expected.to contain_service('keystone').with_before(/Service\[#{platform_parameters[:httpd_service_name]}\]/) }
   end
 
   describe 'when using invalid service name for keystone' do