Updated mediawiki/extensions
Project: mediawiki/extensions/Echo  f551656aa2c2cb722f715e3324b818214675f9d4

Remove EchoEvent::updateExtra, MWEchoBackend::updateEventExtra

Unused functions.
There is also no usecase for this, events shouldn't be altered
after creation except for bundling.

Change-Id: Id175c075d24263119f0455d99342263dd98f9410