drop 3.10 deprecation warning

--HG--
branch : stable

views.py

@@ -54,7 +54,7 @@ class RegistrationFormView(form.FormViewMixIn, StartupView):
 
     def call(self):
         form = self._cw.vreg['forms'].select('registration', self._cw)
-        self.w(form.render(display_progress_div=False))
+        form.render(w=self.w, display_progress_div=False)
 
 class RegistrationSendMailController(controller.Controller):
     __regid__ = 'registration_sendmail'