When a new custom Provider is being added, the cert url is not inferred from main url
I started refactoring the new provider dialog, and I forgot to change ProviderAPI to support that refactor.
I'm sending to ProviderAPI only one parameter (the new provider's main url), and ProviderAPI still thinks he has 3 strings (cert_url, provider_name and eip_service_json_url).
(from redmine: created on 2013-04-15, closed on 2013-04-15)