Cloudflare 关闭 IPv6，源站可以获取到用户客户端的真实IPv4地址，从而做一些处理。

# 关闭 IPv6
curl -X PATCH "https://api.cloudflare.com/client/v4/zones/xxxxxxxxxx/settings/ipv6" \
-H "X-Auth-Email: yourmail@mail.com" \
-H "X-Auth-Key: YourGlobalKey" \
-H "Content-Type: application/json" \
--data '{"value":"off"}'