Section 49A. If a levy on execution shall not have been completed by set-off under the provisions of sections six to twenty-three, inclusive, or by sale under the provisions of sections twenty-six to thirty, inclusive, within six years from the date on which notice of the execution was deposited in a registry of deeds under the provisions of section four, the levy if otherwise then valid shall be void as to any land within such registry district unless within said six-year period it shall be brought forward in such registry of deeds in the manner provided in section one hundred and fourteen A of chapter two hundred and twenty-three for bringing forward attachments of real estate. In case a levy becomes void under the provisions of this section the creditor may resort to any other legal remedy for the satisfaction of his judgment.