Updated mediawiki/extensions
Project: mediawiki/extensions/Flow  21b2d8d359d2861ce0327de0804f5e84c5773879

Repair `Locking a topic` browser test

We now automatically collapse the locked topic on the main
flow-board.  Update test to match.

Change-Id: I8b25ac879984454b11f4e4c1fa69bb7f84ae9498