That was pretty fast. But don't worry too much. It's not a permanent thing. Just walk him around a bit and find him somewhere like Rome where he's got more to do. He won't like sitting around in a (now) border town unless there's more fighting. And the bored trait doesn't hurt you itself, it just makes you more susceptible to finding another way to pass your time. Let's hope he takes a mistress. Have you got one that another fellow has? Maybe you could keep him 'unbored' with one of those.