Add assertion to randrange that input is not 0

Summary:
randrange is not intended to be called with argument 0.

This is a backport of Core PR17293

Test Plan: ninja all check-all

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, jasonbcox

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D8237