diff-hl indicators not shown in fringe

[gekoke]

With catppuccin-theme (mocha variant):

WIth modus-vivendi:

[jtbx]

I've made #186, would you be able to test that out? On my Emacs I can at least see a thin border around the gutter indicators but that should set a concrete colour for the whole thing.

[gekoke]

Yes, that works for me - looks the same as in the image attached to the PR.

[jtbx]

Neat, thanks!