Bug 920701

This fixes the failure from bug 920701.  The linked return by the server  at http://download-akamai.cdn.mozilla.net 
(http://download-akamai.cdn.mozilla.net/pub/mozilla.org/firefox/releases/24.0/win32-EUballot/en-GB/Firefox%20Setup%2024.0.exe) is valid. Users who hit that server will be able to download Firefox without a problem and as such the test should not fail.