Fixed compilation with Stylus 0.32.1

Without removing this I got the following error. I assume its because of the empty block? 

    ParseError: /xxx/responsive-utilities.styl:56
       52| // Print utilities
       53| .visible-print    { display: none !important; }
       54| .hidden-print     { }
       55| 
     > 56| @media print {
       57|   .visible-print  { display: inherit !important; }
       58|   .hidden-print   { display: none !important; }
       59| }

    expected "indent", got "media print"

        at Parser.error (/Users/william/projects/webshaped/node_modules/stylus/lib/parser.js:166:11)
        at Parser.expect (/Users/william/projects/webshaped/node_modules/stylus/lib/parser.js:194:12)
        at Parser.block (/Users/william/projects/webshaped/node_modules/stylus/lib/parser.js:601:12)
        at Parser.selector (/Users/william/projects/webshaped/node_modules/stylus/lib/parser.js:1085:24)
        at Parser.stmt (/Users/william/projects/webshaped/node_modules/stylus/lib/parser.js:550:26)
        at Parser.statement (/Users/william/projects/webshaped/node_modules/stylus/lib/parser.js:460:21)