bad credentials despite normal cli being fine

**Describe the bug**
I can push from the command line normally `git push`, but pushing within `gitui` always fails due to 'bad credentials'.

**To Reproduce**
Commit some changes in `gitui`, press `p` to trigger a push. It always fails.

**Expected behavior**
Pushing should succeed as my ssh key is valid and works outside of gitui.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Context (please complete the following information):**
- OS/Distro : macOS 11, arm m1
- GitUI Version: 0.11.0
- Rust version: 1.49 stable

**Additional context**
`gitui` installed from cargo.