All real property of the association shall be exempt from levy and sale by virtue of an execution, and no execution or other judicial process shall issue against the same nor shall any judgment against the association be a charge or lien upon its real property; provided, however, that the provisions of this section shall not apply to or limit the right of bondholders to foreclose or otherwise enforce any mortgage or other security of the association or the right of obligees and bondholders to pursue any remedies for the enforcement of any pledge or lien given by the association on its rents, fees or revenue or the right of obligees or bondholders to pursue any remedies conferred upon the same pursuant to this act.