Treewide: use HTTPS on GNU domains

HTTP -> HTTPS for :
- http://gnu.org/
- http://www.gnu.org/
- http://elpa.gnu.org/
- http://lists.gnu.org/
- http://gcc.gnu.org/
- http://ftp.gnu.org/ (except in fetchurl mirrors)
- http://bugs.gnu.org/

pkgs/development/tools/gnulib/default.nix

@@ -19,7 +19,7 @@ stdenv.mkDerivation {
   '';
 
   meta = {
-    homepage = http://www.gnu.org/software/gnulib/;
+    homepage = https://www.gnu.org/software/gnulib/;
     description = "Central location for code to be shared among GNU packages";
     license = stdenv.lib.licenses.gpl3Plus;
     platforms = stdenv.lib.platforms.unix;