Issues fixed:
- the cli calls reaching out to the catalog endpoint used to request signature manifests
- resty was used instead of the cli http client to check if the discovery api was available
but it did not take into account TLS verification configuration
(testing locally withself-signed certificates did not work)
(cherry picked from commit ca42031ae9b1ceb459f5cd4f86cb82b3c9f78157)
Signed-off-by: Andrei Aaron <andaaron@cisco.com>