Return to rustours from rus

[Pilen]

When you acces a rus from the rustours page and press either save og cancel you are taken to the rusmanager page instead of coming back.

[Pilen]

We might want to use the mechanics that leads people who hasn't logged in, back to the page they tried to acces when they login.

The mechanic is used in usermanager.login and lib.lytools.logged_in
But we might want to rename the attribute from login_origin to something generic about previous point