licensing: presubmit hook should reject "Proprietary" licenses

BUG=chromium:323243
TEST=None

Change-Id: Ibc6620deebdb4b1bf53bddcd2cb5961287dce819
Reviewed-on: https://chromium-review.googlesource.com/188539
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Marc MERLIN <merlin@chromium.org>
Commit-Queue: Yu-Ju Hong <yjhong@chromium.org>
Tested-by: Yu-Ju Hong <yjhong@chromium.org>
diff --git a/pre-upload.py b/pre-upload.py
index 1776bca..fd556a8 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -601,7 +601,7 @@
   touched_ebuilds = [x for x in affected_paths if x.endswith('.ebuild')]
 
   # A list of licenses to ignore for now.
-  LICENSES_IGNORE = ['||', '(', ')', 'Proprietary']
+  LICENSES_IGNORE = ['||', '(', ')']
 
   for ebuild in touched_ebuilds:
     # Skip virutal packages.