Code review comment for lp:~thomas-noel/fast-user-switch-applet/never-even-max-users

When a system is network managed with libnss-mysql or ldap, it is common to
have 200 users or more...

But for such a system, if I want to set "/apps/fusa/show_screen_item" to
"never" (do not show "Switch User"), it doesn't work because we are in a
"password_overload" case.

So my proposition is to modify the function reset_login_screen_item() in
src/applet.c : it checks if "show_screen_item=never" first.