Updated mediawiki/extensions
Project: mediawiki/extensions/EventLogging  6dd85b9470dfbf8cc473025df99bc8cf37264367
null
Send percent-encoded JSON rather than query params

If/when this gets through review, I'll follow up with a change for the
server-side code.

Change-Id: I66042e439ab8f7c0bd84cd5e94b812474814b6dd