Remove obsolte code

Author: kennethjiang

backend/app/templates/layout.html

@@ -32,7 +32,6 @@
   <link href="https://fonts.googleapis.com/css2?family=Lato:wght@300;400;700&display=swap" rel="stylesheet">
 
   <link rel="stylesheet" type="text/css" href="{% static 'vendor/css/sweetalert2.min.css' %}" />
-  <link rel="stylesheet" type="text/css" href="{% static 'hijack/hijack.min.css' %}" media="screen">
 
   {% bundle 'styles' %}
   {% bundlechunk 'chunk-vendors' 'css' %}