les: limit LES peer count and improve peer configuration logic (#16010)

* les: limit number of LES connections

* eth, cmd/utils: light vs max peer configuration logic

les/server.go

@@ -38,6 +38,7 @@ import (
 )
 
 type LesServer struct {
+	config          *eth.Config
 	protocolManager *ProtocolManager
 	fcManager       *flowcontrol.ClientManager // nil if our node is client only
 	fcCostStats     *requestCostStats
@@ -62,6 +63,7 @@ func NewLesServer(eth *eth.Ethereum, config *eth.Config) (*LesServer, error) {
 	}
 
 	srv := &LesServer{
+		config:           config,
 		protocolManager:  pm,
 		quitSync:         quitSync,
 		lesTopics:        lesTopics,
@@ -108,7 +110,7 @@ func (s *LesServer) Protocols() []p2p.Protocol {
 
 // Start starts the LES server
 func (s *LesServer) Start(srvr *p2p.Server) {
-	s.protocolManager.Start()
+	s.protocolManager.Start(s.config.LightPeers)
 	for _, topic := range s.lesTopics {
 		topic := topic
 		go func() {