'Responds with an `iden` of a new CAPTCHA.
Use this endpoint if a user cannot read a given CAPTCHA,
and wishes to receive a new CAPTCHA.
To request the CAPTCHA image for an iden, use
[/captcha/`iden`](#GET_captcha_{iden}).'

@allow_oauth2_access
@csrf_exempt
@validatedForm()
@api_doc(api_section.captcha)
def POST_new_captcha(self, form, jquery, *a, **kw):

    iden = get_iden()
    jquery('body').captcha(iden)
    form._send_data(iden=iden)
