Updated mediawiki/extensions
Project: mediawiki/extensions/Wikibase  77e89a64ed71ce3edd1862ea9f03d73bf3485de3

Clone Change objects returned by TestChanges.

Previously, test cases would modify the tests and leak state to subsequent tests.

Change-Id: Id9e3f0e82f8de0d6b175ac19457d87e5e40f1134