Case C-170/18 P: Judgment of the Court (First Chamber) of 15 May 2019 — CJ v European Centre for Disease Prevention and Control (ECDC) (Appeal — Civil service — Contract staff — European Centre for Disease Prevention and Control — Fixed-term contract — Termination of the contract — Compliance with a judgment of the European Union Civil Service Tribunal — Res judicata by means of a judgment annulling a decision — Limits)