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/utils.go

@@ -579,12 +579,9 @@ func iamPolicyClaimName() string {
 	return globalOpenIDConfig.ClaimPrefix + globalOpenIDConfig.ClaimName
 }
 
-func isWORMEnabled(bucket string) (Retention, bool) {
+func isWORMEnabled(bucket string) bool {
 	if isMinioMetaBucketName(bucket) {
-		return Retention{}, false
+		return false
 	}
-	if globalWORMEnabled {
-		return Retention{}, true
-	}
-	return globalBucketObjectLockConfig.Get(bucket)
+	return globalWORMEnabled
 }