clique: remove unused import

Author: holiman

consensus/clique/clique.go

@@ -33,13 +33,13 @@ import (
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/crypto/sha3"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc"
 	lru "github.com/hashicorp/golang-lru"
+	"golang.org/x/crypto/sha3"
 )
 
 const (
@@ -667,7 +667,7 @@ func (c *Clique) SealHash(header *types.Header) common.Hash {
 
 // SealHash returns the hash of a block prior to it being sealed.
 func SealHash(header *types.Header) (hash common.Hash) {
-	hasher := sha3.NewKeccak256()
+	hasher := sha3.NewLegacyKeccak256()
 	rlp.Encode(hasher, []interface{}{
 		header.ParentHash,
 		header.UncleHash,