[horde] Adding additional locales

[Simon B]

Hi,

I am not able to find how to add additional locales to Horde.

test.php reports

Supported locales
Deutsch ‭(de_DE): No
‭English (American) ‭(en_US): Yes
‭English (British) ‭(en_GB): Yes

How can I add de_DE?

Thanks.

Simon