p2p: peer score should not wrap around (#8790) (#8792)

(cherry picked from commit 4d820ff4f5)

Co-authored-by: Sam Kleinman <garen@tychoish.com>

internal/p2p/peermanager.go

@@ -1538,6 +1538,10 @@ func (p *peerInfo) Score() PeerScore {
 		score -= int64(addr.DialFailures)
 	}
 
+	if score < math.MinInt16 {
+		score = math.MinInt16
+	}
+
 	return PeerScore(score)
 }