[ES] Record deletion fix

Specs for deletion are in MR https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/654/diffs that is built on top of this MR. I've made it in a separate MR because there is complex stuff left to do. We need another docker image where elastic has plugin delete-by-query

No changelog item required because the bug was introduced in master a few days ago by https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/615