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/data/fonts/gentium-book-basic/default.nix

@@ -19,7 +19,7 @@ in fetchzip rec {
   sha256 = "0598zr5f7d6ll48pbfbmmkrybhhdks9b2g3m2g67wm40070ffzmd";
 
   meta = with stdenv.lib; {
-    homepage = http://software.sil.org/gentium/;
+    homepage = https://software.sil.org/gentium/;
     description = "A high-quality typeface family for Latin, Cyrillic, and Greek";
     maintainers = with maintainers; [ ];
     license = licenses.ofl;

pkgs/data/sgml+xml/schemas/docbook-5.0/default.nix

@@ -28,7 +28,7 @@ stdenv.mkDerivation {
 
   meta = {
     description = "Schemas for DocBook 5.0, a semantic markup language for technical documentation";
-    homepage = http://docbook.org/xml/5.0/;
+    homepage = https://docbook.org/xml/5.0/;
     maintainers = [ lib.maintainers.eelco ];
     platforms = lib.platforms.all;
   };