When api.iternio.com changes CDN provider or reverse proxy configuration we need to import new trusted root CA in OVMS.
api.iternio.com is currently behind Cloudflare.
List of Cloudflare issuing authorities: https://developers.cloudflare.com/ssl/reference/certificate-authorities
Currently the Cloudflare certificates can be issued either by Let's Encrypt or Google Trust Services
Chain of trust https://letsencrypt.org/certificates/
Source for isrgrootx1.pem file : https://letsencrypt.org/certs/isrg-root-x1-cross-signed.pem
Chain of trust https://pki.goog/repository/
Since all Google root CA are cross-signed by GlobalSign it makes more sense to import the GlobalSign certificate.
Source for root-r1.crt file : http://secure.globalsign.com/cacert/root-r1.crt