Fix race in haproxy startup

roles/lb_haproxy/files/haproxy-log-bindmount.conf

@@ -1,7 +1,7 @@
 # haproxy runs in a chroot, so make sure the journald log socket is available there
 [Service]
 # fix log device (points to systemd, but needs to be in the chroot
-ExecStartPre=+/bin/touch /var/lib/haproxy/dev/log
+ExecStartPre=+sh -c 'test -e /var/lib/haproxy/dev/log || /bin/touch /var/lib/haproxy/dev/log'
 ExecStartPre=+/bin/mount -obind /run/systemd/journal/dev-log /var/lib/haproxy/dev/log
 ExecStopPost=-+/bin/umount /var/lib/haproxy/dev/log
 ExecStopPost=-+/bin/rm -f /var/lib/haproxy/dev/log