SSR Always throw http404 and typeerr #1450

Bug Report

Steps to reproduce

npm start

With the documented settings

What is current behaviour

Throw typeerr from node_modules/docsify-server-renderer/build.js:267:27

What is the expected behaviour

Serve the server side rendered site properly

Other relevant information

• Bug does still occur when all/other plugins are disabled?

• Your OS: Linux 5.9.13-arch1-1

• Node.js version: v15.3.0

• npm/yarn version: npm 7.0.5

• Browser version: Chromium 87.0.4280.88 Arch Linux

• Docsify version: 4.4.2

• Docsify plugins: Docsify Search, Click to copy, themeable

Please create a reproducible sandbox

Mention the docsify version in which this bug was not present (if any)