Code review comment for ~dviererbe/casper:lp1990621

Okay, so I double checked if this change would work with a redirect instead of a symlink - and it will! Was worried for a moment that casper might wget one url, get a different filename (due to a redirect) and get confused. But actually it looks like the wget call is using -O so the filename will be called as expected.

This is good to go now. Let me merge.