* Without auth config, the proxy will return 500 errors on
cloud-init requests, which will cause VM connectivity
checks to fail.
* A cleaner fix would be for the metadata proxy to reuse the
configuration from the keystone_authtoken section of
neutron.conf, but I chose the easier route because of a
pending switch from REST to RPC communication (RPC won't
need the auth config).
* Fixes bug 1210664
Change-Id: Iaa3c74f5ada2404119c44c8cbdad380eda158f66
bf10ac55a9