Section 3 of Article XIIIC of the California Constitution, as adopted at the November 5, 1996, general election, shall not be construed to mean that any owner or beneficial owner of a municipal security, purchased before or after that date, assumes the risk of, or in any way consents to, any action by initiative measure that constitutes an impairment of contractual rights protected by Section 10 of Article I of the United States Constitution.