fix(grunt:build): don't copy local.env.sample

closes #1570

Author: Awk34

app/templates/Gruntfile(grunt).js

@@ -424,7 +424,8 @@ module.exports = function (grunt) {
           dest: '<%%= yeoman.dist %>',
           src: [
             'package.json',
-            '<%%= yeoman.server %>/**/*'
+            '<%%= yeoman.server %>/**/*',
+            '!<%%= yeoman.server %>/config/local.env.sample.js'
           ]
         }]
       },