Check for presence of $path/functions/__git.init.fish before sourcing it

[hexclover]

Closes #102.

Test 1: On a home-manager enabled NixOS with fish as default shell, the gst abbreviation works, and SSH with jump host works.
Test 2: On an Arch system with fish as default shell and OMF, the gst abbreviation works.

[jhillyerd]

Can you add a comment or two explaining the why & how of this, it's going to be non-obvious to anyone that isn't familiar with how home-manager works, and I'm unlikely to remember either.

[PaulGrandperrin]

I tried this PR:

        {
          name = "plugin-git"; # git abbrs
          #src = plugin-git.src;
          src = pkgs.fetchFromGitHub {
            owner = "hexclover";
            repo = "plugin-git";
            rev = "master";
            sha256 = "sha256-efKPbsXxjHm1wVWPJCV8teG4DgZN5dshEzX8PWuhKo4";
          };
        }

and it fixes scp for me! thanks :)

[PaulGrandperrin]

I'm using NixOS + HM on unstable FWIW

[jhillyerd]

Thanks!

[GaetanLepage]

Thanks for the fix !
Can you make a git release that would then ship this fix please ?
The plugin-git version in nixpkgs is still v0.1 (Feb. 2023)