fix 修复删除最便宜的方案后，成本不变的bug

model/product/model.go

@@ -96,6 +96,7 @@ func (p *Product) fillPriceStatus(tx *gorm.DB) {
 func (p *Product) CalCNY(calculateProcess []CalculateProcess) {
 	env := p.Env()
 	var calculateStrings = make([]string, 0, len(calculateProcess))
+	p.CNYPrice = 0
 	for _, c := range calculateProcess {
 		process, price := c.Calculate(env)
 		if process != "" {