testing: Converted sql to systemd

testing/tests/sql/shunt-policies-nat-rw/posttest.dat

@@ -1,5 +1,5 @@
-alice::service charon stop 2> /dev/null
-venus::service charon stop 2> /dev/null
-sun::service charon stop 2> /dev/null
+alice::systemctl stop strongswan-swanctl
+venus::systemctl stop strongswan-swanctl
+sun::systemctl stop strongswan-swanctl
 sun::iptables-restore < /etc/iptables.flush
 moon::iptables -t nat -F