[p2p] Fix libp2p version lead the consensus issue (#3868)

* revert libp2p version
* Revert "[p2p] Remove DiscConcurrency code (#3865)"

go.mod

@@ -30,12 +30,12 @@ require (
 	github.com/hashicorp/golang-lru v0.5.4
 	github.com/ipfs/go-ds-badger v0.2.4
 	github.com/json-iterator/go v1.1.10
-	github.com/libp2p/go-libp2p v0.14.4
+	github.com/libp2p/go-libp2p v0.14.0
 	github.com/libp2p/go-libp2p-core v0.8.6
 	github.com/libp2p/go-libp2p-crypto v0.1.0
 	github.com/libp2p/go-libp2p-discovery v0.5.0
-	github.com/libp2p/go-libp2p-kad-dht v0.12.2
+	github.com/libp2p/go-libp2p-kad-dht v0.11.1
-	github.com/libp2p/go-libp2p-pubsub v0.4.2
+	github.com/libp2p/go-libp2p-pubsub v0.4.0
 	github.com/multiformats/go-multiaddr v0.3.3
 	github.com/multiformats/go-multiaddr-dns v0.3.1
 	github.com/natefinch/lumberjack v2.0.0+incompatible

p2p/discovery/option.go

@@ -34,6 +34,12 @@ func (opt DHTConfig) getLibp2pRawOptions() ([]libp2p_dht.Option, error) {
 		opts = append(opts, dsOption)
 	}
 
+	// if Concurrency <= 0, it uses default concurrency supplied from libp2p dht
+	// the concurrency num meaning you can see Section 2.3 in the KAD paper https://pdos.csail.mit.edu/~petar/papers/maymounkov-kademlia-lncs.pdf
+	if opt.DiscConcurrency > 0 {
+		opts = append(opts, libp2p_dht.Concurrency(opt.DiscConcurrency))
+	}
+
 	return opts, nil
 }