Updated mediawiki/extensions
Project: mediawiki/extensions/Flow  e55530c4e4e352b793ed8a2787927efcba0726a0

Hide 'Cancel' button on preview screen

Remove the cancel test in qunit since there is no cancel button
in preview screen anymore

Change-Id: Id9f7fd04702d1b583dc67bb2dcb7505e8b857e83