Fix Keycloak logout URI after multiple calls

Pre-requisites: configure Keycloak and Nuxeo by following the configuration provided on NXP-32352

Steps to reproduce:

1. Navigate to Nuxeo http://localhost:8080/nuxeo
2. The system redirects to Keycloak login page
3. Use the credentials test/test
4. The user "test" is successfully connected
5. Open the Network tab in the Developer tools and filter on "logout"
6. Log out from Nuxeo
7. Observe the logout URL in the Network tab : it contains one time each parameter id_token_hint and post_logout_redirect_uri
8. Log in again with the test user
9. Log out again
10. Observe the logout URL in the Network tab : it contains two times each parameter id_token_hint and post_logout_redirect_uri => this is the bug

You can continue over and over until the logout URL will be too long and the logout will fail

Expected behavior: the logout URL is built with each parameter only once