Set up relationships for nginx::config even when overridden

This keeps the user from having to duplicate them when defining
nginx::config externally.

manifests/init.pp

@@ -281,10 +281,9 @@
       sites_available_owner          => $sites_available_owner,
       sites_available_group          => $sites_available_group,
       sites_available_mode           => $sites_available_mode,
-      require                        => Class['::nginx::package'],
-      notify                         => Class['::nginx::service'],
     }
   }
+  Class['::nginx::package'] -> Class['::nginx::config'] ~> Class['::nginx::service']
 
   class { '::nginx::service':
     configtest_enable => $configtest_enable,