fix 修复 演示页面导出路径错误

ruoyi-ui/src/views/demo/demo/index.vue

@@ -406,7 +406,7 @@ export default {
     },
     /** 导出按钮操作 */
     handleExport() {
-      this.download('demo/demo/export', {
+      this.download('demo/demo/demo/export', {
         ...this.queryParams
       }, `demo_${new Date().getTime()}.xlsx`)
     },