Updated mediawiki/extensions
Project: mediawiki/extensions/BookManagerv2  35abb28e78ff495f587efe2d5fafe55697318d39

Bugfix: Forgotten exclamation point

This was causing seven PHPunit failures, not to mention unwanted
behavior.

Change-Id: Ic69ef7305ce7c78da4f96d367490ba1917228c42