fix case ES preindex

http://manage.dimagi.com/default.asp?147543

depends on https://github.com/dimagi/pillowtop/pull/96
I'm also going to PR https://github.com/dimagi/commcare-hq/commit/576ae829f4fcba371fe9866b14957b7a2fc302c7 as soon as this is merged, and then we can get rid of calc_meta entirely