update:已退费状态退费按钮置灰

src/modules/payment/views/List.vue

@@ -61,7 +61,7 @@
             <el-dropdown-item @click.native="qrCode(row)">发票二维码</el-dropdown-item>
           </el-dropdown-menu>
         </el-dropdown>
-        <el-button @click="backTicket(row)">退费</el-button>
+        <el-button @click="backTicket(row)" :disabled="row.refund_time !== null">退费</el-button>
       </template>
       <template #footer>
         <span>已选择{{ multipleSelection.length }}条</span>