Google broke this when they stopped supporting using Google Drive as storage for web content.
https://gsuiteupdates.googleblog.com/2015/08/deprecating-web-hosting-support-in.html?visit_id=1-636149145676823665-41602563&hl=en&rd=1
They also filter out script tags inside the html for Google Sites now.
I have a fiddle with this http://jsfiddle.net/johnwclark/Q2zTC/