Use JSON encoding for data-replace-with-qr

src/pretix/control/templates/pretixcontrol/organizers/device_connect.html

@@ -2,6 +2,7 @@
 {% load i18n %}
 {% load static %}
 {% load bootstrap3 %}
+{% load escapejson_dumps %}
 {% block inner %}
     <h1>{% trans "Connect to device:" %} {{ device.name }}</h1>
 
@@ -18,7 +19,7 @@
                 {% trans "Open the app that you want to connect and optionally reset it to the original state." %}
             </li>
             <li>{% trans "Scan the following configuration code:" %}<br><br>
-                <script type="text/json" data-replace-with-qr>{{ qrdata|safe }}</script><br>
+                <script type="application/json" data-replace-with-qr>{{ qrdata|escapejson_dumps }}</script><br>
                 {% trans "If your app/device does not support scanning a QR code, you can also enter the following information:" %}
                 <br>
                 <strong>{% trans "System URL:" %}</strong> <code id="system_url">{{ settings.SITE_URL }}</code>

src/pretix/static/pretixcontrol/js/ui/main.js

@@ -874,14 +874,6 @@ function setup_basics(el) {
         });
     });
 
-    el.find(".qrcode-canvas").each(function () {
-        $(this).qrcode(
-            {
-                text: $.trim($($(this).attr("data-qrdata")).html())
-            }
-        );
-    });
-
     el.find(".propagated-settings-box").find("input, textarea, select").not("[readonly]")
         .attr("data-propagated-locked", "true").prop("readonly", true);