fix: support healing older content (#10076)

This PR adds support for healing older
content i.e from 2yrs, 1yr. Also handles
other situations where our config was
not encrypted yet.

This PR also ensures that our Listing
is consistent and quorum friendly,
such that we don't list partial objects

cmd/config-migrate.go

@@ -24,6 +24,7 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
+	"unicode/utf8"
 
 	"github.com/minio/minio/cmd/config"
 	"github.com/minio/minio/cmd/config/cache"
@@ -2506,7 +2507,7 @@ func checkConfigVersion(objAPI ObjectLayer, configFile string, version string) (
 		return false, nil, err
 	}
 
-	if globalConfigEncrypted {
+	if globalConfigEncrypted && !utf8.Valid(data) {
 		data, err = madmin.DecryptData(globalActiveCred.String(), bytes.NewReader(data))
 		if err != nil {
 			if err == madmin.ErrMaliciousData {