Fix noselinux cmdline default (#1137049)
    
    Commit fc8f719114 change the cmdline noselinux behavior but didn't set
    the default to the new -1 value so it would always enable selinux, even
    if the kickstart used selinux --disabled and no cmdline option was
    passed.
    
    This fixes things so that they work as expected. kickstart selinux
    commands work, cmdline overrides only if it has been passed.
    
    Resolves: rhbz#1137049