Notwithstanding any provision in a contract of tenancy of an agricultural holding making the tenant liable to pay a higher rent or other liquidated damages in the event of a breach or non-fulfilment of a term or condition of the contract, the landlord shall not be entitled to recover in consequence of any such breach or non-fulfilment, by distress or otherwise, any sum in excess of the damage actually suffered by him in consequence of the breach or non-fulfilment.