title: Issuer URL in OpenID Connect Discovery should be a working URL?
body: <p>After going through the OpenID Connect Discovery Spec <a href="https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfig" rel="nofollow noreferrer">https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfig</a>, I understand that Issuer is a URL which is used to validate the discovery URL (issuer + "/.well-known/openid-configuration").</p>
  
  <p>I want to know if this issuer URL should be a working URL pointing some resource/service or can be a just valid URL but do not point to any resource. Does this hold significance in any other OpenID Connect flows?</p>