Terminate children in the same process group when monitored PID dies

Really kill them, our monitored process may be about to restart, so we
don't want any unintended side effects from lingering children in prior
instances.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/service.c

@@ -1172,7 +1172,7 @@ void service_monitor(pid_t lost, int status)
 	}
 
 	/* Terminate any children in the same proess group, e.g. logit */
-	kill(-svc->pid, SIGTERM);
+	kill(-svc->pid, SIGKILL);
 
 	/* No longer running, update books. */
 	svc->start_time = svc->pid = 0;