Simplify type test when screen execute button

tryton/tryton/gui/window/view_form/screen/screen.py

@@ -1238,7 +1238,6 @@ class Screen:
             record_id = self.current_record.save(force_reload=False)
             if record_id is False or record_id < 0:
                 return
-        if button.get('type', 'class') == 'class':
             self._button_class(button)
         else:
             self._button_instance(button)