Manage bad ACME certificates

[nmengin]

Do you want to request a feature or report a bug?

Bug

What did you do?

I helped users who had a ACME certificate for a domain with no generated certificate/key in their acme.json file.

    {
      "Domain": {
        "Main": "*.*.foobar.io",
        "SANs": null
      },
      "Certificate": null,
      "Key": null
    }

What did you expect to see?

Træfik retries to generate a valid certificate. Or do not store bad formatted certificates and generate an error message.

What did you see instead?

Error message : Error loading new configuration, aborted unable to generate TLS certificate : tls: failed to find any PEM data in certificate input.

Output of traefik version: (What version of Traefik are you using?)

1.6-RC4 (an older versions I guess)

[traefiker]

Closed by #3191.