Nothing in this division shall, in any manner, operate to release any of the lands excluded from a district from any obligation to pay, or from any lien thereon of, any valid outstanding bonds or other indebtedness of the district at the time of the filing of the petition for exclusion of such lands, but upon the contrary, such lands shall be held subject to such lien and answerable and chargeable for and with the payment and discharge of all of such outstanding obligations at the time of the filing of the petition for exclusion, as fully as though such petition were never filed and the order of exclusion never made.