fleat: update statistics

statistics.php

@@ -321,7 +321,7 @@ while ($row = $detailed_orders->fetch_assoc()) {
     <title>统计分析</title>
     <link rel="stylesheet" href="css/common.css" type="text/css" />
     <script src="system/js/jquery-1.7.2.min.js"></script>
-    <script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
+    <script src="js/chart.js"></script>
     <style>
         body {
             margin: 0;

statistics_header.php

@@ -5,7 +5,7 @@
     <title>统计分析</title>
     <link rel="stylesheet" href="css/common.css" type="text/css" />
     <script src="system/js/jquery-1.7.2.min.js"></script>
-    <script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
+    <script src="js/chart.js"></script>
     <style>
         body {
             margin: 0;