title: /connect/userinfo returns me a 403 forbidden in identityserver4
body: <p>I am using the sample application available with IdentityServer4 : Quickstart6_AspNetIdentity.sln
  Using the ro.client, I am able to get the token.</p>
  
  <p><a href="https://i.stack.imgur.com/JRKgr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JRKgr.png" alt="enter image description here"></a></p>
  
  <p>But when I am using the same token to get the userinfo, I am getting 403 Forbidden error in the same sample. Using the sample as it is.
  Don't know if it is a bug or I am missing something in the parameters. Following all the parameters as mentioned in the document:
  <a href="https://identityserver4.readthedocs.io/en/release/endpoints/userinfo.html" rel="nofollow noreferrer">https://identityserver4.readthedocs.io/en/release/endpoints/userinfo.html</a></p>