use language-subtag-registry as of 2014-12-03

per
https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry

Change-Id: I6e3ca0ff7b8a4608cce3dbc0249ee9ddbf861403
(cherry picked from commit 1914146717e75979120ca63b277078edb6ad6f6c)