/etc/mtab should be labeled as "_", even though systemd has its own
smack label using '--with-smack-run-label' configuration. This is mainly
because all processes could read that file and the origin of this file
(i.e. /proc/mounts) is labeled as "_". This labels /etc/mtab as "_" when
'--with-smack-run-label' is enabled.
We will create the symlink on boot as a fallback to provide name
resolution. But if the symlink was removed afterwards, it most likely
should not be recreated. Creating it only on boot also solves the
issue where it would be created prematurely during installation,
before the system was actually booted.
https://bugzilla.redhat.com/show_bug.cgi?id=1197204
This patch removes unnecessary blank line in
/usr/lib/tmpfiles.d/etc.conf when configured with "--disable-resolved".
(i.e. ENABLE_RESOLVED is not defined)
