Updated mediawiki/extensions
Project: mediawiki/extensions/CentralNotice  3bacfc9293a0dbb90414ce7bb8d99153bfcd070f

Change the update type to index from modify

This solves an issue where a new install which had just run
CentralNotice.sql would attempt to apply this update because
it was not registered in the update table.

Change-Id: I56d34fa7084e71e456858bc1bf59a01ec73d53fa