Increase server affinity grace period (based on testing)

psiphon/config.go

@@ -45,7 +45,7 @@ const (
 	ESTABLISH_TUNNEL_TIMEOUT_SECONDS               = 300
 	ESTABLISH_TUNNEL_WORK_TIME                     = 60 * time.Second
 	ESTABLISH_TUNNEL_PAUSE_PERIOD                  = 5 * time.Second
-	ESTABLISH_TUNNEL_SERVER_AFFINITY_GRACE_PERIOD  = 500 * time.Millisecond
+	ESTABLISH_TUNNEL_SERVER_AFFINITY_GRACE_PERIOD  = 1 * time.Second
 	HTTP_PROXY_ORIGIN_SERVER_TIMEOUT               = 15 * time.Second
 	HTTP_PROXY_MAX_IDLE_CONNECTIONS_PER_HOST       = 50
 	FETCH_REMOTE_SERVER_LIST_TIMEOUT               = 30 * time.Second