with some broken clients allow non-strict validation
of sha256 when ContentLength > 0, it has been found in
the wild some applications that need this behavior. This
shall be only allowed if `--no-compat` is used.
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`