do checkNode() as first thing in HopObject.list()

src/helma/scripting/rhino/HopObject.java

@@ -440,11 +440,11 @@ public class HopObject extends ScriptableObject implements Wrapper {
      * @return ...
      */
     public Scriptable jsFunction_list() {
+        checkNode();
+
         Enumeration e = node.getSubnodes();
         ArrayList a = new ArrayList();
 
-        checkNode();
-
         while ((e != null) && e.hasMoreElements()) {
             a.add(Context.toObject(e.nextElement(), core.global));
         }