Case C-123/17: Judgment of the Court (First Chamber) of 7 August 2018 (request for a preliminary ruling from the Bundesverwaltungsgericht — Germany) — Nefiye Yön v Landeshauptstadt Stuttgart (Reference for a preliminary ruling — EEC-Turkey Association — Decision No 2/76 — Article 7 — Standstill clause — Right of residence of family members of a Turkish worker — Visa requirement for admission to the territory of a Member State)