gn: Incorrect hash for fix-gn-bootstrap.patch

[dylex]

Building gn on master:

trying https://raw.githubusercontent.com/Eloston/ungoogled-chromium/master/resources/patches/ungoogled-chromium/macos/fix-gn-bootstrap.patch
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   830  100   830    0     0   6194      0 --:--:-- --:--:-- --:--:--  6194
fixed-output derivation produced path '/mnt/home/sw/nix/store/2achfpz950qic63sbzs6dq7njv73mz87-fix-gn-bootstrap.patch' with sha256 hash '1rmkn7993z6klqqd2khnwxrkfn49m9hjahdzc6s22w2h4g91l2v5' instead of the expected hash '1h8jgxznm7zrxlzb4wcfx4zx4lyvfrmpd0r7cd7h0s23wn8ibb3a'

Looks like this is downloading the master version of the patch. Changing the url (in pkgs/development/tools/build-managers/gn/default.nix) to the previous fixed version fixes the problem: https://raw.githubusercontent.com/Eloston/ungoogled-chromium/3375fbc7b865dafe1230431a1e3f9bffd27ec184/resources/patches/ungoogled-chromium/macos/fix-gn-bootstrap.patch. However, I'm not sure if the newer version of the patch is preferred. Either way, this should be changed to download from a release, not the master branch.