title: identityserver 4- has no subid when auth from code
body: <p>I have code which auth against Identityserver 4 + entity framework using:
  RequestClientCredentialsTokenAsync</p>
  
  <p>i'm getting token but the after requests has no "sub" or "subid".</p>
  
  <p>do i missing configuration in order to get "sub"?</p>