Gnocchi uses a client with retries=0 to maximize throughtput and not retry N
times on e.g. 404 when checking existence of an object. However, this as the
side effect of never renewing the token since there' no retry on 401 either.
This patches change the behavior so that 401 errors are always retried,
whatever the retries value is.
Closes-Bug: #1589926
Change-Id: Ie06adf4cf17ea4592b5bbd7bbde9828e5e134e3e