Fix pre-login errors in windows

The fix for FA 2.3 in my FAMods repo can be ported safely to FA 2.4 to avoid errors that fill up the tmp/errors.log file each time the login screen is accessed. At that time, there is no user available to the session and the $haystack will be a null resource instead of an array. It should degrade gracefully. This is observed in Windows XAMPP (1.7.3) installs.

@joe: the two functions affected are verbatim in both versions and hence they can be ported easily.