Discovered while using XTools Blame. All WikiWho services fail on the English Wikipedia article Google Play.
URI: https://wikiwho.wmcloud.org/en/api/v1.0.0-beta/latest_rev_content/Google_Play/?o_rev_id=true&editor=true&token_id=true&out=true&in=true
This claims we're missing our SSL certificate (or similar issue), but that is not true, rather some side effect of the WikiWho stack rejecting the request. Locally, WikiWho times out for this article.
We'll need to carefully debug to figure what's going wrong.