Unconditional Right of Holders to Bring Suit for Payment. Notwithstanding any other provision of this Indenture, the right of any Holder to bring suit for the enforcement of payment of principal, premium, if any, Additional Amounts, if any, and interest, if any, on the Notes held by such Holder, on or after the respective due dates expressed in the Notes shall not be impaired or affected without the consent of such Holder.