[NRRPLT-3104] always name light helper geometry

Change-Id: Iadc4a8689c0ada500285e00763bc17d9d9ae68a5

gz3d/src/gzscene.js

@@ -1004,6 +1004,8 @@ GZ3D.Scene.prototype.createLight = function(type, diffuse, intensity, pose,
     lightObj.name = name;
     obj.name = name;
     helper.name = name + '_lightHelper';
+  } else {
+    helper.name = '_lightHelper';
   }
 
   if (direction)