ms-sys: avoid the build timestamp from leaking into the manpage

Also proposed upstream as https://sourceforge.net/p/ms-sys/patches/8/

pkgs/tools/misc/ms-sys/default.nix

@@ -8,6 +8,8 @@ stdenv.mkDerivation rec {
     url = "mirror://sourceforge/ms-sys/${pname}-${version}.tar.gz";
     sha256 = "06xqpm2s9cg8fj7a1822wmh3p4arii0sifssazg1gr6i7xg7kbjz";
   };
+  # TODO: Remove with next release, see https://sourceforge.net/p/ms-sys/patches/8/
+  patches = [ ./manpages-without-build-timestamps.patch ];
 
   nativeBuildInputs = [ gettext ];