fix: syntax error if ctermbg length is not 3
Make sure to execute git in the directory of the current file.

This fixes a problem where wrong gutter markers would appear after navigating
to another place with e.g. 'gf'.
Merge remote-tracking branch 'justinmk/master' into daily-use
fixed @x bug in ctermbg fix
Merge pull request #16 from Droggelbecher/master

Fix git execution with wrong working directory