Namespaced attribute selectors throw csso off

[regiskuckaertz]

Hello, I noticed than with the following CSS:

@namespace xlink "http:https://www.w3.org/1999/xlink";
use > use[xlink|href="#il-"] {
  stroke: currentColor;
}

csso returns with the following error message: Cannot read property '0' of undefined

I'm using grunt-csso which uses the latest version of csso (1.3.11). The same error happens when I type [*|href="..."] as well.

[lahmatiy]

Yep, csso parser didn't support for namespaces in attribute selectors.
Fixed.