setup: fix journalctl configuration

/var/log/journal/*/system.journal does not exist on some systems

https://forum.cloudron.io/topic/4068/installation-failed-on-20-04-server
https://forum.cloudron.io/topic/5731/time4vps-installation-error

setup/start.sh

@@ -80,13 +80,14 @@ sed -e "s/^#SystemMaxUse=.*$/SystemMaxUse=100M/" \
 sed -e "s/^WatchdogSec=.*$/WatchdogSec=3min/" \
     -i /lib/systemd/system/systemd-journald.service
 
-# Give user access to system logs
-usermod -a -G systemd-journal ${USER}
-mkdir -p /var/log/journal  # in some images, this directory is not created making system log to /run/systemd instead
-chown root:systemd-journal /var/log/journal
+usermod -a -G systemd-journal ${USER} # Give user access to system logs
+if [[ ! -d /var/log/journal ]]; then # in some images, this directory is not created making system log to /run/systemd instead
+    mkdir -p /var/log/journal
+    chown root:systemd-journal /var/log/journal
+    chmod g+s /var/log/journal  # sticky bit for group propagation
+fi
 systemctl daemon-reload
 systemctl restart systemd-journald
-setfacl -n -m u:${USER}:r /var/log/journal/*/system.journal
 
 # Give user access to nginx logs (uses adm group)
 usermod -a -G adm ${USER}