Update customGitFetch to reflect env var
Created by: DaedalusG
This is an attached PR to: https://github.com/sourcegraph/sourcegraph/pull/39630, and should not be approved until that PR is also approved
Test Plan
- manually reviewed
- doc update
Created by: DaedalusG
This is an attached PR to: https://github.com/sourcegraph/sourcegraph/pull/39630, and should not be approved until that PR is also approved