NEZ-2687 fix：Explore删除查询表达式后Save chart按钮未置灰

nezha-fronted/src/components/page/dashboard/explore/exploreItem.vue

@@ -4331,6 +4331,7 @@ export default {
         })
         if (!temp) {
           this.showIntroduce = true
+          this.saveDisabled = true
         }
       }
     }