Use different keep alive timeout in tests

Exposes bug found in email discussions resulting from https://github.com/anacrolix/torrent/discussions/547.

config.go

@@ -118,6 +118,9 @@ type ClientConfig struct {
 	// impact of a few bad apples. 4s loses 1% of successful handshakes that
 	// are obtained with 60s timeout, and 5% of unsuccessful handshakes.
 	HandshakesTimeout time.Duration
+	// How long between writes before sending a keep alive message on a peer connection that we want
+	// to maintain.
+	KeepAliveTimeout time.Duration
 
 	// The IP addresses as our peers should see them. May differ from the
 	// local interfaces due to NAT or other network configurations.
@@ -170,6 +173,7 @@ func NewDefaultClientConfig() *ClientConfig {
 		TorrentPeersHighWater:          500,
 		TorrentPeersLowWater:           50,
 		HandshakesTimeout:              4 * time.Second,
+		KeepAliveTimeout:               time.Minute,
 		DhtStartingNodes: func(network string) dht.StartingNodesGetter {
 			return func() ([]dht.Addr, error) { return dht.GlobalBootstrapAddrs(network) }
 		},

peer-conn-msg-writer.go

@@ -37,7 +37,7 @@ func (pc *PeerConn) startWriter() {
 		defer pc.locker().Unlock()
 		defer pc.close()
 		defer pc.locker().Lock()
-		pc.messageWriter.run(time.Minute)
+		pc.messageWriter.run(pc.t.cl.config.KeepAliveTimeout)
 	}()
 }
 

testing.go

@@ -2,6 +2,7 @@ package torrent
 
 import (
 	"testing"
+	"time"
 )
 
 func TestingConfig(t testing.TB) *ClientConfig {
@@ -13,6 +14,7 @@ func TestingConfig(t testing.TB) *ClientConfig {
 	cfg.NoDefaultPortForwarding = true
 	cfg.DisableAcceptRateLimiting = true
 	cfg.ListenPort = 0
+	cfg.KeepAliveTimeout = time.Microsecond
 	//cfg.Debug = true
 	//cfg.Logger = cfg.Logger.WithText(func(m log.Msg) string {
 	//	t := m.Text()