Fixing py lint errors

Bug: webrtc:9548
Change-Id: I0daf8dc06fdaac1637c32994ef6ad542ed52202a
Reviewed-on: https://webrtc-review.googlesource.com/90045
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Reviewed-by: Niklas Enbom <niklas.enbom@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24068}
diff --git a/tools_webrtc/libs/generate_licenses_test.py b/tools_webrtc/libs/generate_licenses_test.py
index 9ac541a..c28a226 100755
--- a/tools_webrtc/libs/generate_licenses_test.py
+++ b/tools_webrtc/libs/generate_licenses_test.py
@@ -16,8 +16,8 @@
                       os.path.dirname((__file__)), os.pardir, os.pardir))
 sys.path.append(os.path.join(SRC, 'third_party', 'pymock'))
 
-import mock
 import unittest
+import mock
 
 from generate_licenses import LicenseBuilder