Updated mediawiki/extensions
Project: mediawiki/extensions/Wikibase  f99ac463cf194e3ab0a2413ec888dd7116d7391f

Make internal storage format configurable

This also stubs out entity serialization on the client,
where it should never be needed.

DEPLOYMENT: We need to tell the repo to keep writing the old
format to the database for now, since the clients don't support
the new format until the new code has been deployed to all wikis:

  'internalEntitySerializerClass'
      => 'Wikibase\Lib\Serializers\LegacyInternalEntitySerializer'

Bug: 66784
Change-Id: I1a425682b6a594557e3beb4dde685004d4eb84e7