@lheckemann already added it to `yarn2nix` a while ago[1], but it seems
as it was forgotten to include when adding `yarn2nix` sources to
`nixpkgs` itself.
Without this patch, you cannot add dependencies to your `package.json`
with URLs like `git://github.com/.../` as building the expression would
fail like this:
```
curl: (1) Protocol "git" not supported or disabled in libcurl
error: cannot download git___github.com_sstur_nodeftpd.git from any mirror
```
Co-authored-by: Linus Heckemann <git@sphalerite.org>
[1] https://github.com/nix-community/yarn2nix/pull/141
