orphan-sysvinit-scripts and systemd conflict. The effect is that in
ci.debian.net this dep would want to change the init system.
What we actually need is rsyslog to be started, which is satisfied
with systemd-sysv since then systemd is the init system and rsyslog
has a systemd unit. (I believe.)
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>