GPG - support for keyring

[antoniaklja]

The GnuPG keyring format has changed, unfortunately, opengpg sdk doesn't support this atm.

https://www.gnupg.org/faq/whats-new-in-2.1.html#nosecring https://github.com/golang/go/issues/29082 https://github.com/helm/helm/issues/2843