Fix regression in iframe embedding for MediaWiki core updates
RL startup module is now loaded asynchronously, so have to stick
things in the window.RLQ queue instead of running them directly.
Recommend a further rewrite of the iframe embed mode later, it's
all a bit scary. :)
Bug: T108359
Change-Id: Ie8a5d47dc3df8301630743c95263736719625c6c
(cherry picked from commit 33e4cbd460f150915059ee16403ffe575588dcd6)