Fixed(#812) not grabbing downloads from AMD driver site

[aymanmostafa11]

Fixes #812

Problem

Sites like Amd driver site prevent the download if it wasn't issued from the browser by checking the referrer header

Solution

Before starting the Httpdownloader headers for referrer and origin are injected into the metadata. the fix was made in a way to allow different referrers to be added easily in the function getReferrer