Updated mediawiki/extensions
Project: mediawiki/extensions/Parsoid  4c6b88b0c327c9183bb55801afdf87e8c8aabadc

ISBN links now parse to mw:ExtLink instead of mw:WikiLink/ISBN

* Cleaned up some code in LinkHandler that handled ISBN.

Change-Id: Iea1d677373e1f2250b7dc3f0eb682d200084366f