Fix typo in help text.

No space between -- and merge.

Review URL: https://chromiumcodereview.appspot.com/10428002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@138562 0039d316-1c4b-4281-b951-d872f2087c98

drover.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-# Copyright (c) 2011 The Chromium Authors. All rights reserved.
+# Copyright (c) 2012 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.