We allow you to omit this callback in the constructor, so make sure it's not null when we go to call it

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5373 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/presents/client/ResultWrapper.as

@@ -40,7 +40,9 @@ public class ResultWrapper extends InvocationAdapter
     // documentation inherited from interface ResultListener
     public function requestProcessed (result :Object) :void
     {
-        _processed(result);
+        if (_processed != null) {
+            _processed(result);
+        }
     }
 
     protected var _processed :Function;