Handle the case when only hidden grants are requested

When no non-hidden grants are requested by the consumer, the message
being output is confusing. Handle that case with a more sensible
message.

Such a client might be useful in certain cases, such as on wikis where
read access is restricted to logged-in users.

Change-Id: I12745b31dd02c2b788c03cd8dce8ec32397be8fc
Merge "Handle the case when only hidden grants are requested"