add an util method to convert []byte to string

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/kms/local.go

@@ -21,6 +21,7 @@ import (
 	"encoding/hex"
 	"io"
 
+	"github.com/drakkan/sftpgo/v2/internal/util"
 	sdkkms "github.com/sftpgo/sdk/kms"
 	"gocloud.dev/secrets/localsecrets"
 	"golang.org/x/crypto/hkdf"
@@ -104,7 +105,7 @@ func (s *localSecret) Decrypt() error {
 		return err
 	}
 	s.Status = sdkkms.SecretStatusPlain
-	s.Payload = string(plaintext)
+	s.Payload = util.BytesToString(plaintext)
 	s.Key = ""
 	s.AdditionalData = ""
 	s.Mode = 0