Describe the bug

When run with vitepress dev docs --base /docs/ and visit /docs route, it will be response with a message:

The server is configured with a public base URL of /docs/ - did you mean to visit [/docs/docs](http://localhost:3000/docs/docs) instead?

I would expect /docs render same as /docs/ or just redirect to /docs/ instead.

Related vuejs/vitepress#852

Reproduction

https://github.com/JounQin/test/tree/vitepress

System Info

System:
    OS: macOS 13.0
    CPU: (10) arm64 Apple M1 Max
    Memory: 20.53 GB / 64.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 16.15.1 - ~/Library/Caches/fnm_multishells/50102_1656090482477/bin/node
    Yarn: 1.22.19 - ~/Library/Caches/fnm_multishells/50102_1656090482477/bin/yarn
    npm: 8.13.1 - ~/Library/Caches/fnm_multishells/50102_1656090482477/bin/npm
  Browsers:
    Chrome: 103.0.5060.53
    Firefox: 101.0.1
    Safari: 16.0
  npmPackages:
    @vitejs/plugin-react: ^1.3.2 => 1.3.2 
    vite: ^2.9.12 => 2.9.12

Used Package Manager

yarn

Logs

N/A

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
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• The provided reproduction is a minimal reproducible example of the bug.