A forfeiture under section 111, clause (g) is waived by acceptance of rent which has become due since the forfeiture, or by distress for such rent, or by any other act on the part of the lessor showing an intention to treat the lease as subsisting:

   Provided that the lessor is aware that the forfeiture has been incurred:

   Provided also that, where rent is accepted after the institution of a suit to eject the lessee on the ground of forfeiture; such acceptance is not a waiver.