Made `render_field()` return `SafeString` when field_instance is None. (#1278)
Made `render_field()` return `SafeString` when field_instance is None. (#1278)

Follow up to 082c8468c7ed3c6302de2201c0cafb71a280c6c3.
django-crispy-forms/django-crispy-forms,django-crispy-forms/django-crispy-forms