texlive (old): mark build as broken

Reported in https://github.com/NixOS/nixpkgs/issues/14807. It's probably
about time to convert to the new texlive code, which is *much* nicer.
See http://nixos.org/nixpkgs/manual/#sec-language-texlive for details.

pkgs/tools/typesetting/tex/texlive/default.nix

@@ -156,5 +156,6 @@ rec {
     maintainers = with maintainers; [ lovek323 raskin jwiegley ];
     platforms   = platforms.unix;
     hydraPlatforms = [];
+    broken = true; # https://github.com/NixOS/nixpkgs/issues/14807
   };
 }