userSettings resource doesn't work properly

Hi,
I’m trying to get keyUiLocale property for a particular user via API. I tried/api/userSettings/keyUiLocale?user=someUsername but it doesn’t return proper results. I guess the problem is here: https://github.com/dhis2/dhis2-core/blob/master/dhis-2/dhis-web/dhis-web-api/src/main/java/org/hisp/dhis/webapi/controller/UserSettingController.java#L159,credentials.getUser() doesn’t return a user with requested username but the owner of credentials object.

Is there some other way to fetch keyUiLocale of a particular user (I need to get keyUiLocale of any user not only current)?

Regards,

Kamil