OF-523: Stop a NullPointerException from occuring when an attempt is made to...

OF-523: Stop a NullPointerException from occuring when an attempt is made to kick an admin (which is not allowed).

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@12987 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/openfire/muc/spi/LocalMUCRoom.java

@@ -1572,7 +1572,7 @@ public class LocalMUCRoom implements MUCRoom {
     public List<Presence> addNone(JID jid, MUCRole senderRole) throws ForbiddenException,
             ConflictException {
     	final JID bareJID = new JID(jid.toBareJID());
-        List<Presence> updatedPresences = null;
+        List<Presence> updatedPresences = Collections.emptyList();
         boolean wasMember = false;
         lock.writeLock().lock();
         try {