update traversedebug preventing traversal to disable OQN

src/osg/OcclusionQueryNode.cpp

@@ -575,7 +575,7 @@ void OcclusionQueryNode::traverseQuery( const Camera* camera, NodeVisitor& nv )
 
 void OcclusionQueryNode::traverseDebug( NodeVisitor& nv )
 {
-    if (_debugBB)
+    if (_debugBB &&  _enabled)
         // If requested, display the debug geometry
         _debugGeode->accept( nv );
 }