Deleted duplicate line

Resources/views/standard_layout.html.twig

@@ -31,7 +31,6 @@ file that was distributed with this source code.
 
             <link rel="stylesheet" href="{{ asset('bundles/sonataadmin/bootstrap/css/bootstrap.min.css') }}" type="text/css" media="all"  />
             <link rel="stylesheet" href="{{ asset('bundles/sonataadmin/bootstrap/css/bootstrap-responsive.min.css') }}" type="text/css" media="all" />
-            <link rel="stylesheet" href="{{ asset('bundles/sonataadmin/bootstrap/css/bootstrap-responsive.min.css') }}" type="text/css" media="all" />
 
             {% if admin_pool is defined and admin_pool.getOption('use_select2') %}
                 <link rel="stylesheet" href="{{ asset('bundles/sonataadmin/select2/select2.css') }}" type="text/css" media="all" />