Issue Type: Bug

After working with a code and before committing anything to a repo, I stashed all changes and started rebase from SourceTree. VS Code showed me conflicts properly. I did all merge operations in Visual Studio 2017, committed and pushed all changes. There was a bunch of other git operations later. I closed and opened VS Code, restarted PC, did some coding, committed and pushed something. But still, I see a warning that I cannot change commit message in the middle of a rebase:

If I try to commit anything from VS Code, I see error popup:

When I press commit button, I see new lines added to git output in VS Code:

git rebase --continue
No rebase in progress?
git config --get-all user.name
git config --get-all user.email

All other git clients working fine and I can do all git operations. Git syncing and branch switching don't help.
git status output:

λ git status
On branch feature/dev-trials-support
Your branch is up to date with 'origin/feature/dev-trials-support'.

Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        modified:   docker-compose.yml

I didn't manage to get rid of this, so I assume there's a bug with the git module.

VS Code version: Code 1.26.1 (493869e, 2018-08-16T18:38:57.434Z)
OS version: Windows_NT x64 10.0.17134