Font shorthand quotes bug

[dmitrijs-pavlovs-dev]

Hello, using quotes to define font name in font shorthand property seem to cause the property to disappear entirely. It seems to happens only during level 2 optimisation, even if all options are turned off by specifying all:false .

Environment

• clean-css version - npm ls clean-css: 4.2.1
• node.js version - node -v: 11.2.0
• operating system: Mac OS

Configuration options

var CleanCSS = require('clean-css');
new CleanCSS({
          level: 2
          },
})

Input CSS

font: 60px/64px "Garamond WF";

Actual output CSS

Expected output CSS

font: 60px/64px "Garamond WF";

[qortex]

Found a workaround: put a generic fallback name. As in angular/angular-cli#9648 (comment).

Here, using "Garamond WF", serif might work?