mtpfs: drop explicit overrides for libmad and libid3tag

  nativeBuildInputs = [ pkg-config ];

  buildInputs = [ fuse libmtp glib libid3tag libmad ];

  # adding LIBS is a hack, duno why it does not find libid3tag.so by adding buildInputs

  preConfigure = ''

    export MAD_CFLAGS=${libmad}/include

    export MAD_LIBS=${libmad}/lib/libmad.so

    export LIBS=${libid3tag}/lib/libid3tag.so

  '';

  src = fetchurl {

    url = "https://www.adebenham.com/files/mtp/mtpfs-${version}.tar.gz";

    sha256 = "07acrqb17kpif2xcsqfqh5j4axvsa4rnh6xwnpqab5b9w5ykbbqv";