treewide: use more HTTPS URLs

Uses the HTTPS url for cases where the existing URL has a permanent
redirect. For each domain, at least one fixed derivation URL was
downloaded to test the domain is properly serving downloads.

Also fixes jbake source URL, which was broken.

pkgs/desktops/lxde/core/lxmenu-data.nix

@@ -12,7 +12,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ intltool ];
 
   meta = {
-    homepage = http://lxde.org/;
+    homepage = https://lxde.org/;
     license = stdenv.lib.licenses.gpl2;
     description = "Freedesktop.org desktop menus for LXDE";
     platforms = stdenv.lib.platforms.linux;

pkgs/desktops/lxde/core/lxpanel/default.nix

@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
 
   meta = {
     description = "Lightweight X11 desktop panel for LXDE";
-    homepage = http://lxde.org/;
+    homepage = https://lxde.org/;
     license = stdenv.lib.licenses.gpl2;
     maintainers = [ stdenv.lib.maintainers.ryneeverett ];
     platforms = stdenv.lib.platforms.linux;