Fix panelize excellon object type

appTools/ToolPanelize.py

@@ -361,7 +361,7 @@ class Panelize(AppTool):
                     obj_fin.zeros = panel_source_obj.zeros
                     obj_fin.units = panel_source_obj.units
                     app_obj.inform.emit('%s' % _("Generating panel ... Adding the source code."))
-                    obj_fin.source_file = self.app.export.export_excellon(obj_name=self.outname, filename=None,
+                    obj_fin.source_file = self.app.f_handlers.export_excellon(obj_name=self.outname, filename=None,
                                                                           local_use=obj_fin, use_thread=False)
                     app_obj.proc_container.update_view_text('')