authelia: Add redirect URL for Headlamp

Now that Headlamp supports PKCE, we can use the same OIDC client for it
as for the Kubneretes API server/`kubectl`.  The only difference is the
callback redirect URL

authelia/configuration.yml

@@ -116,6 +116,7 @@ identity_providers:
       redirect_uris:
       - http://localhost:8000
       - http://localhost:18000
+      - https://headlamp.pyrocufflink.blue/oidc-callback
       authorization_policy: one_factor
       pre_configured_consent_duration: 8h
     - client_id: 1b6adbfc-d9e0-4cab-b780-e410639dc420