Designate: Ensure overriding dns_port

In integration jobs we use non-default port (5322 instead of 53) for
Bind. This change ensures that we use the correct port number.

Change-Id: Ic416e6bd7ebfe4291bf28585d033acd9f7d3b7bc

manifests/designate.pp

@@ -87,6 +87,7 @@ class openstack_integration::designate {
 
   class { 'designate::backend::bind9':
     rndc_host        => '127.0.0.1',
+    dns_port         => 5322,
     rndc_config_file => '/etc/rndc.conf',
     rndc_key_file    => $::dns::params::rndckeypath,
     manage_pool      => true