Indicate that "not found" may actually be a permission issue

We now restrict visibility to user dashboards, but there is the UX
problem that the client aggressively generates dashboard links that
now may return "not found." Ideally we would include a visibility bit
in the account information returned over every RPC, but that will
require some work, so until then, just give a slightly less confusing
error message.

Change-Id: Ie52033e0af31a962b186ddf75119e45ddb150de3
1 file changed