ttyrec: mark as broken

Requires svr4-specific stuff to work around "out of ptys"-error[1],
however this API has been dropped in glibc 2.30 and as the package is
fairly old, there doesn't seem to be an actual fix available.

[1] mjording/ttyrec#2

pkgs/tools/misc/ttyrec/default.nix

@@ -26,5 +26,6 @@ stdenv.mkDerivation rec {
     license = licenses.bsd3;
     platforms = platforms.all;
     maintainers = with maintainers; [ zimbatm ];
+    broken = true; # 2020-01-28
   };
 }