Fix message for GitHub fork reference in zh.json

[gjssss]

[nginxproxymanagerci[bot]]

Docker Image for build 1 is available on DockerHub:

nginxproxymanager/nginx-proxy-manager-dev:pr-4944

[!NOTE] Ensure you backup your NPM instance before testing this image! Especially if there are database changes. This is a different docker image namespace than the official image.

[!WARNING] Changes and additions to DNS Providers require verification by at least 2 members of the community!