We have scripting bug, when /var/log/journal exists, install.sh does not generate scylla_sysconfdir.py.
Stop generating scylla_sysconfdir.py in if else condition, do that
unconditionally in install.sh, also drop pre-generated
scylla_sysconfdir.py from dist/common/scripts.
Also, $rsysconfdir is correct path to point nonroot mode sysconfdir,
instead of $sysconfdir.
Fixes#8385Closes#8386