[fix] handle weights in accept language parsing - fixes w3ms en;q=1.0

def _get_browser_language(request, lang_list):

    for lang in request.headers.get("Accept-Language", "en").split(","):

        if ';' in lang:

            lang = lang.split(';')[0]

        locale = match_language(lang, lang_list, fallback=None)

        if locale is not None:

            return locale

    return settings['search']['default_lang'] or 'en'

@babel.localeselector