Fixed for anonymous users.

git-svn-id: http://svn.igniterealtime.org/svn/repos/messenger/trunk@776 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/messenger/handler/PresenceUpdateHandler.java

@@ -173,7 +173,7 @@ public class PresenceUpdateHandler extends BasicModule implements ChannelHandler
     private void initSession(Session session)  throws UnauthorizedException, UserNotFoundException {
 
         // Only user sessions need to be authenticated
-        if (!"".equals(session.getAddress().getNode())) {
+        if (session.getAddress().getNode() != null && !"".equals(session.getAddress().getNode())) {
             String username = session.getAddress().getNode();
             Roster roster = rosterManager.getRoster(username);
             for (RosterItem item : roster.getRosterItems()) {