Displaying only one option at 2FA stage will allow to add more options
like DUO push or OAuth.
The user can switch to other option and in this case the option is
remembered so that next time, the user will see the same option. The
latest option is considered as the prefered option by Authelia.
Authelia client uses hash router instead of browser router in order to work
with Kubernetes nginx-ingress-controller. This is also better for users having
old browsers.
This commit is breaking because it requires to change the configuration of the
proxy to include the # in the URL of the login portal.
