Every instrument conveying, encumbering, or creating a lien upon real estate shall set forth in words and figures the correct amount of the note secured by the instrument and the date upon which the note falls due. When the note falls due within three years from the date of the note or from the date of any instrument executed to secure the note, a statement of that fact in lieu of specifying the date upon which the note falls due may be made in the security instrument and shall constitute sufficient compliance with this Code section. The inclusion in the instrument of a provision that the instrument secures all other indebtedness then existing or thereafter incurred shall not require the setting forth in the instrument of existing indebtedness for loans not made on the security of the instrument.