Fix bug preventing overwrite of object if (#8796)

object lock config is enabled for a bucket.

Creating a bucket with object lock configuration
enabled does not automatically cause WORM protection
to be applied. PUT operation needs to specifically
request object locking or bucket has to have default
retention settings configured.

Fixes regression introduced in #8657

cmd/object-lock.go

@@ -477,8 +477,7 @@ func enforceRetentionBypassForPut(ctx context.Context, r *http.Request, bucket,
 	ret := getObjectRetentionMeta(oi.UserDefined)
 	// no retention metadata on object
 	if ret.Mode == Invalid {
-		_, isWORMBucket := isWORMEnabled(bucket)
-		if !isWORMBucket {
+		if _, isWORMBucket := globalBucketObjectLockConfig.Get(bucket); !isWORMBucket {
 			return oi, ErrInvalidBucketObjectLockConfiguration
 		}
 		return oi, ErrNone
@@ -527,7 +526,7 @@ func checkPutObjectRetentionAllowed(ctx context.Context, r *http.Request, bucket
 	var mode RetentionMode
 	var retainDate RetentionDate
 
-	retention, isWORMBucket := isWORMEnabled(bucket)
+	retention, isWORMBucket := globalBucketObjectLockConfig.Get(bucket)
 
 	retentionRequested := isObjectLockRequested(r.Header)