请问添加这段防火墙规则的目的是什么

[YuxuanZuo]

具体位置在

OpenClash/luci-app-openclash/root/usr/share/openclash/openclash_watchdog.sh

Lines 95 to 102 in dd5e07d

	local position=$(nft -a list chain inet fw4 dstnat |grep "OpenClash" |grep "DNS" |awk -F '# handle ' '{print$2}' |sort -rn |head -1)
	[ -z "$position" ] && position=0
	nft add rule inet fw4 dstnat position "$position" tcp dport 53 redirect to "$DNSPORT" comment \"OpenClash DNS Hijack\" 2>/dev/null
	nft add rule inet fw4 dstnat position "$position" udp dport 53 redirect to "$DNSPORT" comment \"OpenClash DNS Hijack\" 2>/dev/null
	if [ "$ipv6_enable" -eq 1 ]; then
	nft add rule inet fw4 dstnat position "$position" meta nfproto {ipv6} tcp dport 53 counter redirect to "$DNSPORT" comment \"OpenClash DNS Hijack\" 2>/dev/null
	nft add rule inet fw4 dstnat position "$position" meta nfproto {ipv6} udp dport 53 counter redirect to "$DNSPORT" comment \"OpenClash DNS Hijack\" 2>/dev/null
	fi

这部分上面的代码已经清除了DNS劫持规则，为什么这里又要重新添加？