Migration fails, log.set_data(log.tmp_data) does not exist.

[vdboor]

The migration 0009 fails, because it tries to use a model method, which does not exist in the South ORM:

        for log in orm['form_designer.FormLog'].objects.all():
            log.set_data(log.tmp_data)
            log.save()

The set_data() method is not available in South.