Prevent early auth deny in tempauth when using swift3 middleware.

When tempauth is used together with swift3 and keystone, groups are
empty and tempauth denies the request too early without a chance for
keystone to authenticate the request.

Change-Id: I21d9b22ecbd18a5f1fba901abd94221a332c45ea
Closes-Bug: 1244545
Merge "Prevent early auth deny in tempauth when using swift3 middleware."