Quixey: Use HTTP instead of HTTPS for the image links.

@yegg @moollaza 

I made a function called toHTTP which returns the HTTP version of icon_url. It gets the domain name of the image server that it finds in the platforms array, and it uses that to replace the domain name of the icon_url. It's not ideal, but it seems to work pretty well.

https://jagtalon.duckduckgo.com/?q=flight+tracking+apps

**Edit:** This is a fix for #276