[PATCH] Clean environment for GIT test

[Bert Wesarg]

Unset GIT_DIR and GIT_WORK_TREE environment variable in test
test-vc-list-files-git.sh.

---
diff --git i/tests/test-vc-list-files-git.sh w/tests/test-vc-list-files-git.sh
--- i/tests/test-vc-list-files-git.sh
+++ w/tests/test-vc-list-files-git.sh
@@ -28,6 +28,9 @@ tmpdir=vc-git-$$
 trap 'st=$?; cd '"`pwd`"' && rm -rf $tmpdir; exit $st' 0
 trap '(exit $?); exit $?' 1 2 13 15

+unset GIT_DIR
+unset GIT_WORK_TREE
+
 fail=1
 mkdir $tmpdir && cd $tmpdir &&
  # without git, skip the test