avoid attempting to migrate old configs (#17004)

cmd/iam-etcd-store.go

@@ -25,7 +25,6 @@ import (
 	"strings"
 	"sync"
 	"time"
-	"unicode/utf8"
 
 	jsoniter "github.com/json-iterator/go"
 	"github.com/minio/minio-go/v7/pkg/set"
@@ -115,26 +114,6 @@ func (ies *IAMEtcdStore) saveIAMConfig(ctx context.Context, item interface{}, it
 	return saveKeyEtcd(ctx, ies.client, itemPath, data, opts...)
 }
 
-func decryptData(data []byte, itemPath string) ([]byte, error) {
-	var err error
-	if !utf8.Valid(data) && GlobalKMS != nil {
-		data, err = config.DecryptBytes(GlobalKMS, data, kms.Context{
-			minioMetaBucket: path.Join(minioMetaBucket, itemPath),
-		})
-		if err != nil {
-			// This fallback is needed because of a bug, in kms.Context{}
-			// construction during migration.
-			data, err = config.DecryptBytes(GlobalKMS, data, kms.Context{
-				minioMetaBucket: itemPath,
-			})
-			if err != nil {
-				return nil, err
-			}
-		}
-	}
-	return data, nil
-}
-
 func getIAMConfig(item interface{}, data []byte, itemPath string) error {
 	data, err := decryptData(data, itemPath)
 	if err != nil {