Multi language website shows English website, I want Dutch language #480

Hi
I have installed Screenly ose en configured my raspberry pi locales with nl_NL.UTF-8. (That is Dutch)
But a website shows the English website when it is multi language. When I visit this website from a deskop browser, it is in Dutch language.
As I understand, the browser is Uzbl-browser in Screenly OSE
How can I configure Uzbl that it will take the Dutch language? Or what should I do to fix this?

Thanks.

Erik Nieuwenhuis