Fixes #6367 - cnsmer_shw auth client/usr BZ1112664

access denied received when registering using subscription-manger using the
consumerId flag was for a preliminary call to check that the consumer
exists. This allows :consumer_show authorization through client or user
instead of solely by client.
Merge pull request #4338 from dustint-rh/subman_consumer_reg

Fixes #6367 - cnsmer_shw auth client/usr BZ1112664