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/data/documentation/std-man-pages/default.nix

@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
 
   meta = {
     description = "C++ STD manual pages";
-    homepage = http://gcc.gnu.org/;
+    homepage = https://gcc.gnu.org/;
     license = "GPL/LGPL";
     platforms = stdenv.lib.platforms.unix;
   };

pkgs/data/fonts/freefont-ttf/default.nix

@@ -19,7 +19,7 @@ fetchzip rec {
       (PostScript Type0, TrueType, OpenType...) fonts covering the ISO
       10646/Unicode UCS (Universal Character Set).
     '';
-    homepage = http://www.gnu.org/software/freefont/;
+    homepage = https://www.gnu.org/software/freefont/;
     license = stdenv.lib.licenses.gpl3Plus;
     platforms = stdenv.lib.platforms.all;
     maintainers = [];

pkgs/data/misc/miscfiles/default.nix

@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
   };
 
   meta = with stdenv.lib; {
-    homepage = http://www.gnu.org/software/miscfiles/;
+    homepage = https://www.gnu.org/software/miscfiles/;
     license = licenses.gpl2Plus;
     description = "Collection of files not of crucial importance for sysadmins";
     maintainers = with maintainers; [ pSub ];