Make sure that the currently-set language is the one that shows on the left sidebar if no language  preference exists.

Some students were confused by the display on the sidebar when it would say 'English' even if the text was in another language. This should fix the problem.

@flowerhack @sarina @stephensanchez 

ECOM-135
Yup, basically. I know that would interfere with Dark Lang stuff if we were setting the language preferences in the DB here. Some students were just getting confused because their sidebar said that their preferred language was English, even though their sessions were in their browser's language.