Unless a certificate showing military service is filed as required by section 281.273, it shall be presumed that the owner of the property described in the notice of expiration of the time for redemption from delinquent taxes is not in such service. The filing of the certificate provided for in section 281.273 shall not affect the forfeiture of the real property described in such notice of the expiration of the time for redemption from delinquent taxes or their proceedings relating thereto except as expressly herein provided.