Fix logout URI with Keycloak

Currently the logout URI uses the parameter "redirect_uri", for example

http://localhost:8087/realms/barmig/protocol/openid-connect/logout?redirect_uri=http://localhost:8080/nuxeo/ui/

=> it throws an error "Invalid parameter: redirect_uri"

The parameter "post_logout_redirect_uri" should be used instead of "redirect_uri". Besides that another parameter must be added to the logout URI :

• either "client_id" set to the keycloak realm => in this case, the customer is asked to confirm the logout
• either "id_token_hint" (better solution) => in this case, the logout is automatic