[A17] Hostile tribes lose relations to manhunters

[Mehni]

What happens:
I got raided by a tribal with a stick. Simultaneously, a rabbit went mad and killed the raider. I lost 5 goodwill points to this.

What you expected to happen.
That's a difficult one. I'm okay with losing reputation, but losing reputation to a faction that's already hostile towards me is a bit nonsensical. I'd prefer to remain ignorant of this; suppress all reputation messages from hostile factions.

Repro steps:
1. Spawn a raid of a faction that's appreciative.
2. Spawn a bunch of manhunters. Enough to overcome the raid, or at least guarantee some casualties.
3. Observe the faction relation status messages.

[ison]

Fixed for A18, thanks.