Updated mediawiki/extensions
Project: mediawiki/extensions/Flow  ff30248fb12d2036573d5113c88e789b497f6623

Abstract out DbStorage superclass from BasicDbStorage and RevisionStorage.

Also make sure that RevisionStorage has the security improvements from 64bf13a

Change-Id: Ia00a6f96f3ac23085f43b5f6bfc8bae88b8e21b0