It's caused by a script that's detecting the protocol, however since it's a
file, it's not valid. Look for the below in your html file.

if (document.location.protocol != "index.html") {document.location =
document.URL.replace(/^http:/i, "index.html");}

I'm not sure if this is added by HTTrack or if it's part of Wordpress (which
is what I'm copying)