Trying to add a shared field throws an error:

Fatal error:  Uncaught Error: Call to undefined method Tracker_FormElement_Shared::getCSRFTokenForElementUpdate() in /usr/share/tuleap/plugins/tracker/include/Tracker/FormElement/View/Admin/CreateVisitor.php:59
Stack trace:
#0 /usr/share/tuleap/plugins/tracker/include/Tracker/FormElement/Tracker_FormElementFactory.php(1568): Tracker_FormElement_View_Admin_CreateVisitor->display()
#1 /usr/share/tuleap/plugins/tracker/include/Tracker/Tracker.php(723): Tracker_FormElementFactory->displayAdminCreateFormElement()
#2 /usr/share/tuleap/plugins/tracker/include/Tracker/TrackerManager.php(151): Tracker->process()
#3 /usr/share/tuleap/plugins/tracker/include/Tracker/TrackerManager.php(169): TrackerManager->processSubElement()
#4 /usr/share/tuleap/plugins/tracker/include/TrackerPluginDefaultController.php(45): TrackerManager->process()
#5 /usr/share/tuleap/src/common/Request/FrontRouter.php(251): Tuleap\Tracker\TrackerPluginDefaultController->process()
#6 /usr/share/tuleap/src/common/Request/FrontRouter.php(109): Tuleap\Request\FrontRouter->routeHandler()
#7 /usr/share/tuleap/src/www/index.php(50): Tuleap\Request\FrontRouter->route()
#8 {main}
  thrown in /usr/share/tuleap/plugins/tracker/include/Tracker/FormElement/View/Admin/CreateVisitor.php on line 59

Introduced by request #41857.