Scheme is missing from static_configs

[PietroPasotti]

          Scheme is missing.

But we need to think about the topology we target here:

• for in cluster scrape (by the same prom that is proxied by trfk?), we would need to use insecureSkipVerify, as the cert that would be served is for the external hostname.
• for out-of-cluster scrape, we would need to give the external hostname and need prom/gagent to have a receive-ca-cert relation (relate to the external ca)

Originally posted by @sed-i in #269 (comment)

[lucabello]

@PietroPasotti is this still relevant?

[lucabello]

I don't think this is still relevant, because we now always pass through Traefik if there is an ingress relation. Closing, but please re-open if I'm wrong :)