Remove unnecessary js variable; fixes linter error

resources/css/default.scss

 @import "../../node_modules/reset-css/sass/_reset.scss";
 @import "../../node_modules/purecss/build/pure.css";
-$fa-font-path: '../fonts/';
 @import "../../node_modules/\@fortawesome/fontawesome-free/scss/fontawesome";
 @import "../../node_modules/\@fortawesome/fontawesome-free/scss/solid";
 @import "../../node_modules/highlight.js/styles/zenburn.css";