Judgment of the Court (Fifth Chamber) of 5 February 2004 in Case C-265/02 (Reference for a preliminary ruling from the Corta suprema di cassazione): Frahuil SA v Assitalia SpA (Brussels Convention — Special jurisdiction — Article 5(1) — Meaning of "matters relating to a contract" — Contract of guarantee entered into without the knowledge of the principal debtor — Subrogation of the guarantor to the rights of the creditor — Right of recourse of the guarantor against the principal debtor)