The related change [1] causes expiring object records to no longer be
created if the X-Delete-At-Container header is not sent to the object
server, but old proxies prior to [2] (i.e. releases prior to 1.9.0)
did not send this header.
The goal of [1] can be alternatively achieved by making expiring
object record creation be conditional on the X-Delete-At-Host header.
[1] Related-Change: I20fc2f42f590fda995814a2fa7ba86019f9fddc1
[2] Related-Change: Id0873a3f2198ce285fe0b0c777738eff38bc2438
Change-Id: Ia0081693f01631d3f2a59612308683e939ced76a
dfa0c4e604