CSS HMR remove the host in the URL

[RomainLanz]

Hey! 👋

When working with CSS, the HMR code of Vite removes the host in the URL.

This may not create an issue when working on a front-end setup, but when integrating with a back-end system like Laravel, Rails, or AdonisJS, it will break the loading of the asset.

This issue only appears in development since after a production build, the assets are served by the back-end.

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As state per the documentation, we should add the full host to the URL of our assets.

<link rel="stylesheet" href="http://localhost:3000/css/app.css">

After one HMR, this is rewritten like the following.

<link rel="stylesheet" href="/css/app.css">

Therefore, it will not reach Vite server and will fail to load the file.

Related: #1539