Track ffos_privacy.lang for locales with template

Stop tracking privacy/ffos_privacy.lang for "de", "el", "es-ES", and "pl" since they're using the old system (full .lang file).

Start tracking privacy/ffos_privacy.lang as a minimal file (only strings used in the form, title, etc.) for "hu", "it", "pt-BR", "sr". The rest of the page is in a custom template.