Revert "Remove obsolete xml-rpc version"

This reverts commit 5017e24756199689b197db81f8b3e0de3ba5d454.

pkgs/applications/editors/emacs-modes/xml-rpc/default.nix

@@ -0,0 +1,32 @@
+{stdenv, fetchurl, emacs}:
+
+stdenv.mkDerivation rec {
+  name = "xml-rpc-1.6.8";
+
+  src = fetchurl {
+    url = https://launchpadlibrarian.net/40270196/xml-rpc.el;
+    sha256 = "0i8hf90yhrjwqrv7q1f2g1cff6ld8apqkka42fh01wkdys1fbm7b";
+  };
+
+  phases = [ "buildPhase" "installPhase"];
+
+  buildInputs = [ emacs ];
+
+  buildPhase = ''
+    cp $src xml-rpc.el
+    emacs --batch -f batch-byte-compile xml-rpc.el
+  '';
+
+  installPhase = ''
+    install -d $out/share/emacs/site-lisp
+    install xml-rpc.el* $out/share/emacs/site-lisp
+  '';
+
+  meta = {
+    description = "Elisp implementation of clientside XML-RPC";
+    homepage = https://launchpad.net/xml-rpc-el;
+    license = stdenv.lib.licenses.gpl3Plus;
+
+    platforms = stdenv.lib.platforms.all;
+  };
+}

pkgs/top-level/all-packages.nix

@@ -12383,6 +12383,8 @@ in
 
     writeGood = callPackage ../applications/editors/emacs-modes/writegood { };
 
+    xmlRpc = callPackage ../applications/editors/emacs-modes/xml-rpc { };
+
     cask = callPackage ../applications/editors/emacs-modes/cask { };
   };