* treewide: http -> https sources
This updates the source urls of all top-level packages from http to
https where possible.
* buildtorrent: fix url and tab -> spaces
The original URL for this package was pointed at a location that wasn't
longterm-stable, and has by now been removed by Debian.
This commit fixes the URL to point at a debian snapshot entry, which should
stick around for the long run.
Hash is unchanged, so this is safe.
