Case T-321/15: Judgment of the General Court of 10 November 2015 — GSA and SGI v Parliament (Public service contracts — Tendering procedure — Supply of fire security, assistance to persons and external surveillance at the European Parliament’s site — Rejection of a tenderer’s bid — Obligation to produce prior authorisation issued pursuant to national legislation — Proportionality — Equal Treatment — Principle of openness — Freedom to provide services)