appveyor doesn't clone shallow

appveyor.yml

@@ -23,7 +23,7 @@ init:
 
 build_script:
   - git config --replace-all remote.origin.fetch +refs/heads/*:refs/remotes/origin/*
-  - git fetch --unshallow
+  - git fetch
   - git checkout %APPVEYOR_REPO_BRANCH%
   - git reset --hard %APPVEYOR_REPO_COMMIT%
   - python -m pip install -r requirements.txt