Contracts of indemnity; no obligation of community

property unless signed by both husband and wife. It is against the public policy of this state to allow one spouse to obligate community property by entering into a contract of indemnity whereby he will indemnify a surety company in case of default of the principal upon a bond or undertaking issued in consideration of the contract of indemnity. No community property shall be liable for any indebtedness incurred as a result of any contract of indemnity made after the effective date of this section, unless both husband and wife sign the contract of indemnity.