For some reason, we have USER_LOGIN set to 'false' for the KDE
package set install test. I really don't know / remember why
that would be; I'd think we should create a user and log in as
that user to make sure it works properly when installing KDE
from the traditional installer. It's not strictly part of the
package set test, true, but still, seems worth doing.
Also, when USER_LOGIN is set to 'false' and the installer runs,
we create a user called 'false'. This doesn't seem like what we
wanted, so let's not do that. I dunno if there are any other
cases besides the KDE one that this commit changes, but still.