test-cert generation scripts: Fix root certs that weren't getting extensions added.

BUG=none
R=rsleevi@chromium.org

Review URL: https://codereview.chromium.org/147723003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248667 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248667