Case C-32/19: Judgment of the Court (Tenth Chamber) of 22 January 2020 (request for a preliminary ruling from the Oberster Gerichtshof — Austria) — AT v Pensionsversicherungsanstalt (Reference for a preliminary ruling — Freedom of movement for persons — Citizenship of the Union — Right to move and reside freely in the territory of the Member States — Directive 2004/38/EC — Article 17(1)(a) — Right of permanent residence — Acquisition before completion of a continuous period of five years of residence — Workers who, at the time they stop working, have reached the age for entitlement to an old age pension)