Workaround for Fog Swift bug

This patch works around a bug in Fog where, if Swift is unavailable, Fog will
throw an unexpected error instead of simply indicating that the service is
unavailable.

This patch will have to suffice until we can get a patch into Fog and update to
the latest community version.

https://bugzilla.redhat.com/show_bug.cgi?id=1130309
Would it be better to implement this in raw_connect?
Just in case there's a client that calls raw_connect directly.