Fix for non-functioning Remember Me login feature

[smg6511]

What does it do?

Casts rememberme property to boolean to ensure proper functionality.

Why is it needed?

User sessions are not persisted even when use checks Remember Me during login.

How to test

1. Set your session_cookie_lifetime system setting to a short time (I set it to 180 [3 minutes]).
2. Login without checking Remember Me and verify that, when quitting the browser (while still logged in), you are NOT automatically logged in when re-opening the browser and revisiting the manager
3. Login with Remember Me checked and, within the 3 minutes (or whatever lifetime you set), quit and re-open the browser to verify automatic login is functioning.
4. Again, before your 3 minute session lifetime has expired, quit the browser (while still logged in).
5. After the 3 minutes has elapsed, open your browser again to verify you are NOT automatically logged in.

Related issue(s)/PR(s)

Resolves #16518