Update Bootstrap to 3.4.1

Fixes:

CVE-2018-20676
CVE-2019-8331
CVE-2018-20677
CVE-2018-14042
CVE-2016-10735
CVE-2018-14040

Author: rafaelncarvalho

Diff for: docker/rootfs/var/www/html/index.html

@@ -5,7 +5,7 @@
         <meta http-equiv="X-UA-Compatible" content="IE=edge">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <title>Default Site</title>
-        <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
+        <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet">
         <style>
             .jumbotron { margin-top: 50px; }
         </style>