authenticated identifier attached to OrgIdentity always labeled as ePPN

When a self-signup enrollment flow is configured with Require Enrollee Authentication the authenticated identifier consumed from REMOTE_USER is attached to the OrgIdentity with identifier type ePPN. 

Since the value in REMOTE_USER may not be an ePPN, for example when authentication is done with an OIDC flow, the identifier should not be automatically labeled as an ePPN.