notificationDaemon: Fix urgency hint

We currently mark notifications as urgent which merely contain the
'urgent' property, even when set to false. Look at the actual value
instead.

https://bugzilla.gnome.org/show_bug.cgi?id=710596

js/ui/notificationDaemon.js

@@ -732,7 +732,8 @@ const GtkNotificationDaemonNotification = new Lang.Class({
               "default-action": defaultAction,
               "default-action-target": defaultActionTarget } = notification;
 
-        this.setUrgency(urgent ? MessageTray.Urgency.CRITICAL : MessageTray.Urgency.NORMAL);
+        this.setUrgency(urgent.unpack() ? MessageTray.Urgency.CRITICAL
+                                        : MessageTray.Urgency.NORMAL);
 
         if (buttons) {
             buttons.deep_unpack().forEach(Lang.bind(this, function(button) {