Updated mediawiki/extensions
Project: mediawiki/extensions/Parsoid  64921430b1dcbcf6b17481e13b4bf4faa24b43b9

Freeze some static values in WikiConfig

Any changes to these would be bugs, and could lead to weird effects like
loading templates from another wiki.

Makes sure any attempt to modify the default values fails by freezing those
values.

Change-Id: Id198fcd285b179d9efa3698affe7e97bff95900b