treewide: Change URLs to HTTPS

Lots of URLs were HTTP redirect to HTTPS. Changed those and checked them
if there's actual content. Inspired by
https://github.com/NixOS/nixpkgs/issues/60004

pkgs/applications/networking/p2p/frostwire/frostwire-bin.nix

@@ -22,7 +22,7 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with stdenv.lib; {
-    homepage = http://www.frostwire.com/;
+    homepage = https://www.frostwire.com/;
     description = "BitTorrent Client and Cloud File Downloader";
     license = licenses.gpl2;
     maintainers = with maintainers; [ gavin ];