Updated JS libraries (#50)

(I just like keeping stuff up to date, I had no real problems with the older versions)

index.php

@@ -307,9 +307,9 @@ $opcache = OpCacheService::init($options);
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width,initial-scale=1.0">
     <title>OPcache statistics on <?php echo $opcache->getData('version', 'host'); ?></title>
-    <script src="//cdn.jsdelivr.net/react/15.4.2/react.min.js"></script>
-    <script src="//cdn.jsdelivr.net/react/15.4.2/react-dom.min.js"></script>
-    <script src="//cdn.jsdelivr.net/jquery/3.1.1/jquery.min.js"></script>
+    <script src="//cdn.jsdelivr.net/react/15.5.4/react.min.js"></script>
+    <script src="//cdn.jsdelivr.net/react/15.5.4/react-dom.min.js"></script>
+    <script src="//cdn.jsdelivr.net/npm/jquery@3.5.0/dist/jquery.min.js"></script>
     <style type="text/css">
         .opcache-gui { font-family:sans-serif; font-size:90%; padding: 0; margin: 0; }
         .opcache-gui .hide { display: none; }