Send users whose sessions have expired to the login page.

(imported from commit 9ffdc414b9a0874d2cd6f7a4f91596b82390ab38)

static/js/setup.js

@@ -28,7 +28,7 @@ $(function () {
             // We got logged out somehow, perhaps from another window or a session timeout.
             // We could display an error message, but jumping right to the login page seems
             // smoother and conveys the same information.
-            window.location.replace('/accounts/login');
+            window.location.replace(page_params.login_page);
         }
     });