Judgment of the Court (Second Chamber) of 2 June 2005 in Case C-15/04: Reference for a preliminary ruling from the Bundesvergabeamt Koppensteiner GmbH v Bundesimmobiliengesellschaft mbH (Public procurement — Directive 89/665/EEC — Review procedures concerning the award of public procurement contracts — Decision to withdraw an invitation to tender after the opening of tenders — Judicial review — Scope — Principle of effectiveness)