csr（renderClient方法）和ssr（render方法）渲染模式混用报错
## What happens?
复现步骤
1、使用easywebpack cli，初始化一个项目
1）全局安装easywebpack
2）easywebpack init，初始化一个项目，如下图
![image](https://user-images.githubusercontent.com/7248432/102175879-3998b080-3edb-11eb-9a9b-c31510822c04.png)

3）修改admin.ts的代码，ctx.ssr的状态可以由接口动态的控制，自行实现(比如使用自定义的cookie)
![image](https://user-images.githubusercontent.com/7248432/102175890-3e5d6480-3edb-11eb-99fe-777f51300202.png)

2、启动服务 npm run dev

3）访问http://local.test.com:7001/ 走的是renderClient方法（因为ctx.ssr默认是undefined）

4）访问http://local.test.com:7001/admin

5）再次访问http://local.test.com:7001/ 报错
![image](https://user-images.githubusercontent.com/7248432/102176670-dc9dfa00-3edc-11eb-8c46-9ad359e18956.png)
2020-12-15 13:49:19,015 ERROR 54504 [-/127.0.0.1/-/23ms GET /] nodejs.TypeError: Cannot read property 'matched' of undefined
    at render (/Users/haha/work/test/demo1/node_modules/vue-router/dist/vue-router.common.js:356:25)
    at createFunctionalComponent (/Users/haha/work/test/demo1/node_modules/vue/dist/vue.runtime.common.dev.js:3052:30)
    at createComponent (/Users/haha/work/test/demo1/node_modules/vue/dist/vue.runtime.common.dev.js:3225:12)
    at _createElement (/Users/haha/work/test/demo1/node_modules/vue/dist/vue.runtime.common.dev.js:3415:15)
    at createElement (/Users/haha/work/test/demo1/node_modules/vue/dist/vue.runtime.common.dev.js:3347:10)
    at vm._c (/Users/haha/work/test/demo1/node_modules/vue/dist/vue.runtime.common.dev.js:3484:42)
    at Proxy.render (webpack:///./app/web/component/layout/admin/content/index.vue?./node_modules/vue-loader/lib/loaders/templateLoader.js??vue-loader-options!./node_modules/vue-loader/lib??vue-loader-options:12:8)
    at Vue._render (/Users/haha/work/test/demo1/node_modules/vue/dist/vue.runtime.common.dev.js:3538:22)
    at resolve (/Users/haha/work/test/demo1/node_modules/vue-server-renderer/build.dev.js:8656:28)
    at waitForServerPrefetch (/Users/haha/work/test/demo1/node_modules/vue-server-renderer/build.dev.js:8287:3)
    at render (/Users/haha/work/test/demo1/node_modules/vue-server-renderer/build.dev.js:8658:5)
    at Object.renderToString (/Users/haha/work/test/demo1/node_modules/vue-server-renderer/build.dev.js:9183:9)
    at /Users/haha/work/test/demo1/node_modules/egg-view-vue-ssr/lib/engine.js:137:21
    at new Promise (<anonymous>)
    at Engine.renderString (/Users/haha/work/test/demo1/node_modules/egg-view-vue-ssr/lib/engine.js:136:12)
    at Engine.renderClient (/Users/haha/work/test/demo1/node_modules/egg-view-vue-ssr/lib/engine.js:155:17)

## Context
- **Node Version**: 12.16.0
- **Egg Version**:  2.29.1
- **Plugin Name**:
- **Plugin Version**:
- **Platform**: mac os
