Scylla now supports server-defined systemd slices that are used to provide
isolation between components.
This patch adds scylla-jmx to the helper slice. This will guarantee that
scylla-jmx does not use too much resources, influencing the server performance.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Since systemd unit can override parameters using drop-in unit, we don't need
mustache template for them.
Also, drop --disttype option on install.sh since it does not required anymore,
introduce --sysconfdir instead for non-redhat distributions.