gsutil ls -l changed format.
Is causing silent errors in generated indexes.
This fixes the imediate failure, future CL coming so failure won't be silent
in the future.

BUG=None
TEST=None
TBR=nsylvain

Review URL: http://codereview.chromium.org/3331006

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/gsd_generate_index@58244 0039d316-1c4b-4281-b951-d872f2087c98