Merge branch 'jk/http-walker-limit-redirect'

Merge branch 'jk/http-walker-limit-redirect'

Update the error messages from the dumb-http client when it fails
to obtain loose objects; we used to give sensible error message
only upon 404 but we now forbid unexpected redirects that needs to
be reported with something sensible.

* jk/http-walker-limit-redirect:
  http-walker: complain about non-404 loose object errors