Revert "Enforce the current year in license blurb."

This reverts commit 2237a6cf56ade5755856f388c900abba04791756

BUG=chromium-os:33326
TEST=repo allows any copyright year in changed files.

Change-Id: I7d5e7a66beb0cc70b07982e3f3862ce6a41eedb4
Reviewed-on: https://gerrit.chromium.org/gerrit/29374
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: David James <davidjames@chromium.org>
Tested-by: David James <davidjames@chromium.org>
diff --git a/pre-upload.py b/pre-upload.py
index 6e993c5..7b3db58 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -1,10 +1,9 @@
 #!/usr/bin/env python
-# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import ConfigParser
-import datetime
 import json
 import optparse
 import os
@@ -308,9 +307,8 @@
 
 def _check_license(project, commit):
   """Verifies the license header."""
-  year = str(datetime.datetime.now().year)
   LICENSE_HEADER = (
-     r".*? Copyright \(c\) " + year + " The Chromium OS Authors\. All rights "
+     r".*? Copyright \(c\) 20[-0-9]{2,7} The Chromium OS Authors\. All rights "
        r"reserved\." "\n"
      r".*? Use of this source code is governed by a BSD-style license that can "
        "be\n"