Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  12ec4364ac5ad7fa63dcf5a32da28f6d86b587f2

Regression: Fix "Start uploading" button on lead uploads tutorial

Its label was missing and it would do nothing because the overlay
got closed before the event was dispatched.

Change-Id: If45b51c77077ad21552880c04c5d5a9e0bb1bc64