This fixes commit 5e354b2252 which was an attempt to avoid installation
of tmpfiles.d/systemd-remote.conf when it was not needed (ie HAVE_REMOTE=false).
Before this fix and with the autotool build, systemd-remote.conf was
distributed and also installed (although it was empty) even though
HAVE_REMOTE=false.
That's what happens when doing last second changes without retesting...
While at it, update tmpfiles.d/.gitignore (var.conf was missing as well
since commit a083537e5d).
Choose which system users defined in sysusers.d/systemd.conf and files
or directories in tmpfiles.d/systemd.conf, should be provided depending
on comile-time configuration.
Franck Bui