Only check subID when requester is subscribed to the node (when accessing items). JM-665

git-svn-id: http://svn.igniterealtime.org/svn/repos/wildfire/trunk@3831 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/wildfire/pubsub/PubSubEngine.java

@@ -997,7 +997,7 @@ public class PubSubEngine {
 
         // Get the user's subscription
         NodeSubscription subscription = null;
-        if (node.isMultipleSubscriptionsEnabled()) {
+        if (node.isMultipleSubscriptionsEnabled() && !node.getSubscriptions(owner).isEmpty()) {
             if (subID == null) {
                 // No subid was specified and the node supports multiple subscriptions
                 Element pubsubError = DocumentHelper.createElement(