/// Either the height at which this channel was created or the height at which it was last
/// serialized if it was serialized by versions prior to 0.0.103.
/// We use this to close if funding is never broadcasted.
/// Either the height at which this channel was created or the height at which it was last
/// serialized if it was serialized by versions prior to 0.0.103.
/// We use this to close if funding is never broadcasted.