§ 324. Effect of recording assignment of mortgage. The recording of an assignment of a mortgage is not in itself a notice of such assignment to a mortgagor, his heirs or personal representatives, or to an owner of the mortgaged premises where such assignment is recorded subsequent to the recording of the conveyance of such premises to such owner, so as to invalidate a payment made by either of them to the mortgagee or to a prior assignee of the mortgage.