Removed duplicate lines

production/index.html

@@ -15,8 +15,6 @@
     <link href="../vendors/font-awesome/css/font-awesome.min.css" rel="stylesheet">
     <!-- NProgress -->
     <link href="../vendors/nprogress/nprogress.css" rel="stylesheet">
-    <!-- NProgress -->
-    <link href="../vendors/nprogress/nprogress.css" rel="stylesheet">
     <!-- iCheck -->
     <link href="../vendors/iCheck/skins/flat/green.css" rel="stylesheet">
     <!-- bootstrap-progressbar -->
@@ -1281,4 +1279,4 @@
     </script>
     <!-- /gauge.js -->
   </body>
-</html>
+</html>