Seems like your setting is set in settings/override/file.ini[.append.php] or settings/siteaccess/*/file.ini[.append.php] It should be like this in 4.1.x (this is from settings/file.ini):
Optimally we shouldn't have used the same setting in 4.1 when we changed it, for notice on this and other bc breaks have a look in the bc doc ( doc/bc/4.1/changes-4.1.0.txt ).