(bug 47305) Add /zh-mo as an alias for wikipedia.org/w/index.php

With zh-mo enabled in bug 47204 (I5806a17d), MediaWiki starts to
generate /zh-mo links which returns 404.

Bug: 47305
Bug: 47204
Change-Id: I50dfaa270fb4729ac65478326b40452872078cb6
Merge "(bug 47305) Add /zh-mo as an alias for wikipedia.org/w/index.php"