fix：资产展示显示问题

src/views/billing/plan.vue

@@ -185,8 +185,8 @@ export default class Plan extends Vue {
           } else if (this.PricingPlanList[i].assetType === 3) {
             this.PricingPlanList[i].assetTypeShow = 'Free'
           }
-          this.PricingPlanList[i].endDate = this.PricingPlanList[i].endDate.replace(/-/g, '/')
-          this.PricingPlanList[i].startDate = this.PricingPlanList[i].startDate.replace(/-/g, '/')
+          this.PricingPlanList[i].endDate = this.PricingPlanList[i].endDate?.replace(/-/g, '/')
+          this.PricingPlanList[i].startDate = this.PricingPlanList[i].startDate?.replace(/-/g, '/')
         }
       }
     }).catch(err => {