document the flags field, and combine flags in the rpki example;

ok deraadt

src/etc/crontab

@@ -1,4 +1,4 @@
-#	$OpenBSD: crontab,v 1.27 2020/04/16 23:36:52 job Exp $
+#	$OpenBSD: crontab,v 1.28 2020/04/18 17:22:43 jmc Exp $
 #
 # /var/cron/tabs/root - root's crontab
 #
@@ -6,7 +6,7 @@ SHELL=/bin/sh
 PATH=/bin:/sbin:/usr/bin:/usr/sbin
 HOME=/var/log
 #
-#minute	hour	mday	month	wday	command
+#minute	hour	mday	month	wday	[flags] command
 #
 # rotate log files every hour, if necessary
 0	*	*	*	*	/usr/bin/newsyslog
@@ -19,4 +19,4 @@ HOME=/var/log
 30	5	1	*	*	/bin/sh /etc/monthly
 #~	*	*	*	*	/usr/libexec/spamd-setup
 
-#~	*	*	*	*	-s -n rpki-client -v && bgpctl reload
+#~	*	*	*	*	-ns rpki-client -v && bgpctl reload