redirect stderr to dev null since the rule might not exist when we try to unconditionally delete it

(This used to be ctdb commit e1d709f32196e19d4041ee2958e143791762e08f)

ctdb/config/events.d/10.interface

@@ -114,7 +114,7 @@ case $cmd in
 		fi
 	    done
 	}
-	iptables -D INPUT -i $iface -d $ip -j DROP
+	iptables -D INPUT -i $iface -d $ip -j DROP 2> /dev/null
 	[ $failed = 0 ] || {
 		 echo "Failed to del $ip on dev $iface"
 		 exit 1