change page navigation

lib/pages/rates/discount_by_weight_editor.dart

@@ -4,6 +4,7 @@ import 'package:fcs/localization/app_translations.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/widgets/input_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
@@ -39,8 +40,7 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
 
   @override
   Widget build(BuildContext context) {
-
-     final weightBox = InputText(
+    final weightBox = InputText(
         labelTextKey: 'rate.discount.weight',
         iconData: FontAwesomeIcons.weightHanging,
         controller: _weightController);
@@ -55,9 +55,7 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
         appBar: AppBar(
           centerTitle: true,
           leading: new IconButton(
-            icon: new Icon(
-              Icons.close,
-            ),
+            icon: new Icon(CupertinoIcons.back),
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,