Serve draft whitehall assets from whitehall-admin
Serve draft whitehall assets from whitehall-admin

Requests to draft-origin for draft whitehall assets get routed to
draft-whitehall-frontend, which serves these files directly from NFS.

This is unlike the behaviour for www-origin, which redirects to
assets-origin.  We want to redirect draft-origin too, so we send the
request on to whitehall-admin.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet