See https://pagure.io/atomic-wg/issue/341 - basically for libostree
(and hence rpm-ostree, and Fedora Editions that use it like Fedora Atomic Host),
the Anaconda selinux --enforcing verb will end up rewriting
/etc/selinux/config to the same value it had before.

But because of the trailing space character, this generates
a difference, and means the config file appears locally modified,
and hence deployed systems won't receive updates.

I think Anaconda should also be fixed to avoid touching the file at all
if it wouldn't result in a change, but let's remove the trailing space
here too, as it's better to fix in two places.