Use autonotify in keystone_domain_config

This was not supported in older Puppet 3 as
suggested by the comment but has been available
for a long time now.

Change-Id: I1353953484582c8b3fa3af96fb4fa44d67c61bdf

lib/puppet/type/keystone_domain_config.rb

@@ -7,17 +7,12 @@ Puppet::Type.newtype(:keystone_domain_config) do
   # to openstack cli
   extend PuppetX::KeystoneConfig::IniSetting
 
-  def initialize(*args)
-    super
-    # latest version of puppet got autonotify, but 3.8.2 doesn't so
-    # use this.
-    keystone_service = 'Service[keystone]'
-    self[:notify] = [keystone_service] if !catalog.nil? &&
-      catalog.resource(keystone_service)
-  end
-
   create_parameters
 
+  autonotify(:service) do
+    ['keystone']
+  end
+
   # if one declare the domain directory as a resource, this will
   # create a soft dependancy with it.
   autorequire(:file) do