cmd, les: remove light client code (ethereum#28586)

Author: gzliudan

cmd/XDC/main.go

@@ -89,8 +89,8 @@ var (
 		utils.TxPoolLifetimeFlag,
 		utils.SyncModeFlag,
 		utils.GCModeFlag,
-		//utils.LightServFlag,
-		//utils.LightPeersFlag,
+		// utils.LightServFlag,  // deprecated
+		// utils.LightPeersFlag, // deprecated
 		//utils.LightKDFFlag,
 		utils.CacheFlag,
 		utils.CacheDatabaseFlag,
@@ -327,11 +327,6 @@ func startNode(ctx *cli.Context, stack *node.Node, cfg XDCConfig) {
 	}()
 	// Start auxiliary services if enabled
 
-	// Mining only makes sense if a full Ethereum node is running
-	if ctx.String(utils.SyncModeFlag.Name) == "light" {
-		utils.Fatalf("Light clients do not support staking")
-	}
-
 	var ethereum *eth.Ethereum
 	if err := stack.Service(&ethereum); err != nil {
 		utils.Fatalf("Ethereum service not running: %v", err)