Fix logging error for automated emails

src/pretix/base/models/orders.py

@@ -2212,7 +2212,7 @@ class OrderPosition(AbstractPosition):
         :param attach_ical: Attach relevant ICS files
         """
         from pretix.base.services.mail import (
-            SendMailException, mail, render_mail,
+            SendMailException, TolerantDict, mail, render_mail,
         )
 
         if not self.attendee_email:
@@ -2225,6 +2225,7 @@ class OrderPosition(AbstractPosition):
             recipient = self.attendee_email
             try:
                 email_content = render_mail(template, context)
+                subject = str(subject).format_map(TolerantDict(context))
                 mail(
                     recipient, subject, template, context,
                     self.event, self.order.locale, order=self.order, headers=headers, sender=sender,

src/pretix/control/templates/pretixcontrol/order/mail_history.html

@@ -28,7 +28,7 @@
                             <br/><span class="fa fa-fw fa-envelope-o"></span> {{ log.parsed_data.recipient }}
                         {% endif %}
                     </p>
-                    {% if log.parsed_data.subject.items %}
+                    {% if log.parsed_data.message.items %}
                         <div class="alert alert-info">
                             {% blocktrans trimmed %}
                                 This email has been sent with an older version of pretix. We are therefore not able to