I would contest it and if I lost, appeal. Courts don't like to waste time on stuff like this and there's a good chance there wouldn't even be a second court appearance. Even if you're in one of those jurisdictions that are ramping up revenue with ticket quotas that can work. But mainly it really is a truly petty ticket. Those lights with sensors that never change for a bike, what you did would have been perfectly legal. What's difference did it make really, between this light and one of those if there was no traffic and no danger? Or maybe you got "confused" and thought that was the situation with this light.