Remove duplicate require

Author: Sambego

Gruntfile.js

@@ -5,7 +5,6 @@ module.exports = (grunt) => {
     grunt.loadNpmTasks("grunt-contrib-copy");
     grunt.loadNpmTasks("grunt-contrib-stylus");
     grunt.loadNpmTasks("grunt-contrib-pug");
-    grunt.loadNpmTasks("grunt-contrib-pug");
     grunt.loadNpmTasks("grunt-webpack");
     grunt.loadNpmTasks("grunt-contrib-watch");
     grunt.loadNpmTasks("grunt-contrib-clean");