Small change to staticweb with container requests. Before, a request
to a container that had no x-container-meta-web-index and no
x-container-meta-web-listings would pass the request on to the proxy
server, even if x-web-mode was set to true. Now, if x-web-mode is set
true, it will 404.
This mostly important to folks that are using staticweb with an
external service that uses authenticated requests and x-web-mode set
to true, in which case the above 404 previously would return the
container listing (you were authenticated after all). Unauthenticated
requests would have received 401s anyway.
Change-Id: Ifd321a8a076a79c1e119c5259a40bf08defdbe3c