Section 21. Decree on the basis of a first mortgage to be satisfied by the sale of mortgaged property.

21. Notwithstanding anything contained in rule 6 or rule 8-A of Order XXXIV of the First Schedule of the Code of Civil Procedure, 1908, where in a suit based on a loan secured by a first mortgage a decree for sale has been executed and the net proceeds of the sale of the mortgaged property are found insufficient to pay the amount due to the plaintiff or to the defendant, as the case maybe, no decree shall be passed for the balance due to such plaintiff or defendant, as the case may be, and if any decree for such balance has been passed before the commencement of this Act, it shall be deemed to have been satisfied.