Support css url(/static/img/stuff.png)

[cepm-nate]

In a recent project, I had a CSS rule (In the <style> section of a .vue file) that used background-image: url(/static/image.png).

This worked fine in DEV mode, but building and deploying to android (or double-clicking the www/index.html file) resulted in the image resolving to a 404.
Changing the css rule on-the-fly to remove the leading slash (url(static/image.png) made the image load. But removing the slash in the SOURCE make the build fail (MiniCssExtractPlugin threw "unable to resolve" errors).

My workaround is to REMOVE that rule from the <style> section of the file and inject it dynamically in mounted() as url(static/image.png). Thankfully I only have one background image I'm setting this way.

I'm reporting this here, as I think people using this template would expect url() to work with /static/ resources in their <style> section.

Thanks for all your hard work!