Updated mediawiki/extensions
Project: mediawiki/extensions/Flow  9eb6256fdff1092a135c7954bf1588656b9a7b9a

Hygiene: Remove unused BoardHistory formatter class

This class was removed in Ic5087e7d7a66a32602d403e9b13c586add732ebd
but made it back in.  It is unused and is savely removed.

Change-Id: I0386dff2f20954892467981687ac31269f71e127