This happens because of a change added where any sub-credential
with parentUser == rootCredential i.e (MINIO_ROOT_USER) will
always be an owner, you cannot generate credentials with lower
session policy to restrict their access.
This doesn't affect user service accounts created with regular
users, LDAP or OpenID
This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`