Merge pull request #3839 from sasha0/fix/notification_body

Do not escape HTML in the notification body on the customer notification detail page.

src/oscar/templates/oscar/communication/notifications/detail.html

             </tr>
             <tr>
                 <th>{% trans 'Body' %}</th>
-                <td>{{ notification.body }}</td>
+                <td>{{ notification.body|safe }}</td>
             </tr>
         {% else %}
             <tr>