I don't think there is, and that's there just in case you either lose your programmed fingertip in an industrial accident or sutures etc, or you encounter some hardware failure and the fingerprint scanner no longer works, or perhaps a software blip like fingerprint data is lost. I see a lot of gripes here about wonky fingerprint issues. If you find a way to bypass, I'd strongly recommend against it. No print, no backup PIN, the phone is useless and Google will not help you unlock it.