Blog list sort uncorrect after upgrade to 1.8.0

[bougieL]

• vuepress version: 1.2.0
• @vuepress/plugin-blog version: 1.8.0

• I confirm that this is an issue rather than a question.

Bug report

Steps to reproduce

• This issue doesn't need a reproduction repro, here is the steps to reproduce

• Server render sorter is different to client render sorter.
• Page will flash when enter the site first.
• Here is the configs.
• @vuepress/plugin-blog config.

[
    '@vuepress/blog',
    {
      directories: [
        {
          id: 'blog',
          dirname: 'blog',
          path: '/',
          frontmatter: {
            title: '博客'
          },
          pagination: {
            perPagePosts: 12
          }
        },
        {
          id: 'daily',
          dirname: 'daily',
          path: '/daily/',
          frontmatter: {
            title: '日常'
          },
          pagination: {
            perPagePosts: 12
          }
        }
      ]
    }
  ]

• Frontmatter

title: 十二种常见算法思想汇总
author: 全民学编程
date: 2020-01-02
tags:
  - Banyun
coverImg: /images/2020/01/02/1.jpeg
description: 算法：枚举、递推、递归、分治、贪心、试探法、动态迭代和模拟等算法思想。

What is expected?

What is actually happening?

Other relevant information

• npx vuepress info:

Environment Info:

  System:
    OS: macOS 10.15.2
    CPU: (4) x64 Intel(R) Core(TM) i5-7500 CPU @ 3.40GHz
  Binaries:
    Node: 10.16.0 - ~/.nvm/versions/node/v10.16.0/bin/node
    Yarn: 1.21.1 - ~/.yarn/bin/yarn
    npm: 6.12.0 - ~/.nvm/versions/node/v10.16.0/bin/npm
  Browsers:
    Chrome: 79.0.3945.117
    Firefox: 70.0.1
    Safari: 13.0.4
  npmPackages:
    @vuepress/core:  1.2.0 
    @vuepress/theme-default:  1.2.0 
    vuepress: ^1.2.0 => 1.2.0 
  npmGlobalPackages:
    vuepress: Not Found

[bougieL]

I have downed to version 1.7.1, and the sorter is correct even in the safari.

[billyyyyy3320]

Thanks for the report.