add warning when no bootstrap in config

License: MIT
Signed-off-by: Kejie Zhang <601172892@qq.com>

core/bootstrap.go

@@ -117,7 +117,9 @@ func bootstrapRound(ctx context.Context, host host.Host, cfg BootstrapConfig) er
 	// get bootstrap peers from config. retrieving them here makes
 	// sure we remain observant of changes to client configuration.
 	peers := cfg.BootstrapPeers()
-
+	if len(peers) == 0 {
+		log.Warning("no bootstrap in the configuration file")
+	}
 	// determine how many bootstrap connections to open
 	connected := host.Network().Peers()
 	if len(connected) >= cfg.MinPeerThreshold {