git-cl: Run using vpython

Bug: 1002153
Change-Id: I02ffa574f072575c4b6662a7f32678428ed3f85d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1845498
Reviewed-by: Anthony Polito <apolito@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
diff --git a/git_cl.py b/git_cl.py
index 378744b..4aa2275 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env vpython
 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.