bug#45113: scummvm download link changed

[Matthew Brooks]

The old link ("http://www.scummvm.org/frs/scummvm/2.2.0/scummvm-2.2.0.tar.xz";) 
now just silently gives the html content of the main page instead of a 404 or 
anything.

The new link is 
"https://downloads.scummvm.org/frs/scummvm/2.2.0/scummvm-2.2.0.tar.xz"; Only 
differences appear to be that it's now https, and resides under the "downloads" 
subdomain instead of "www". The file itself has the same hash, and the scummvm 
package built fine after I updated the URL.