gup: use SRI hash and fix updateScript

stdenv.mkDerivation rec {

  version = "0.9.2";

  src = fetchFromGitHub {

    hash = "sha256-bV5HauM0xmRI/9Pxp1cYLPLA8PbFvPER2y4mAMmgchs=";

    owner = "timbertson";

    repo = "gup";

    rev = "version-0.9.2";

    sha256 = "06vjl34h09ifvc8z3g65yvqc1wic31bsgwfkzx469iilwdm4fpkd";

    rev = "version-${version}";

  };

  pname = "gup";

  nativeBuildInputs = [ python3 which pylint ];

        --set repo gup \

        --set type fetchFromGitHub \

        --set rev 'version-{version}' \

        --nix-literal rev 'version-''${version}'\

        --modify-nix default.nix

    ''

  ];