We still has "{{^jessie}}" tag on scylla-server systemd unit file to
skip using AmbientCapabilities on Debian 8, but it does not able to work
anymore since we moved to single binary .deb package for all debian variants,
we must share same systemd unit file across all Debian variants.
To do so we need to have separated file on /etc/systemd to define
AmbientCapabilities, create the file while running postinst script only
if distribution is not Debian 8, just like we do in .rpm.
See #3344
See #3486
Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Message-Id: <20190619064224.23035-1-syuu@scylladb.com>