HTTPS is canceled by Browser and my request is regarded as a HTTP requeset

fetch('http://ift.tt/2kBUMxF')
  .then(resp => resp.json())
  .then(json => console.log(json))

I tried to fetch my json data from my gh-pages (gh-pages' Access-Control-Allow-Origin is *)

By what I get is this:

what code I use and what I get

and I checked the network panel in Chrome's devtool:

network panel in Chrome's devtool

the https request is canceled by browser, my fetch is regarded as a http request.