Fix build broekn by r142988.
https://bugs.webkit.org/show_bug.cgi?id=109530

Unreviewed. Build fix.

Properly add shortMonthFormat() to the LocaleNone class.

Patch by Alberto Garcia <agarcia@igalia.com> on 2013-02-19

* platform/text/LocaleNone.cpp:
(LocaleNone):
(WebCore::LocaleNone::shortMonthFormat):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143320 268f45cc-cd09-0410-ab3c-d52691b4dbfc