Run rndc reload instead of restarting bind

It looks like restarting bind immediately after a zone file update
may be a bad idea and may lead to corrupted journal files.  Instead,
issue a rndc reload which is much gentler.

Change-Id: I237183315e877709e93eaba8ab5435c9c71b21ba

modules/openstack_project/manifests/master_nameserver.pp

@@ -14,7 +14,7 @@ define openstack_project::master_zone (
     source  => $source,
     recurse => remote,
     require => File['/var/lib/bind/zones'],
-    notify  => Service[$::dns::namedservicename],
+    notify  => Exec['rndc_reload'],
   }
   file { "/etc/bind/keys/${name}":
     require => File['/etc/bind/keys'],
@@ -117,4 +117,10 @@ class openstack_project::master_nameserver (
     require => Vcsrepo['/opt/zone-zuul-ci.org'],
   }
 
+  exec { 'rndc_reload' :
+    command     => 'rndc reload',
+    path        => '/sbin:/usr/sbin:/bin:/usr/bin',
+    refreshonly => true,
+  }
+
 }