Large objects manifest object etag problem

[miya]

Hi,
Indicates that verification is optional with "etag" and "size_bytes" while creating a SLO manifest file.

Although we get "201 Created" response when we try to create SLO manifest without "etag" and "size_bytes" in request, we get "502 Bad Gateway" when we try to download the manifest.

It work correctly when we create SLO manifest with etag and size_bytes, we can download it.

-----------------------------------
Release: 2.30.0.dev85 on 2017-10-03 00:11:07
SHA: cbe032ab5142fffe1419eb569bb9ecee5c668706
Source: https://opendev.org/openstack/swift/src/doc/source/api/large_objects.rst
URL: https://docs.openstack.org/swift/latest/api/large_objects.html