Backport a migration

src/pretix/plugins/ticketoutputpdf/migrations/0003_auto_20180805_1432.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.13 on 2018-08-05 14:32
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+def cleanup(app, schema_editor):
+    EventSettingsStore = app.get_model('pretixbase', 'Event_SettingsStore')
+    EventSettingsStore.objects.filter(key='ticketoutput_pdf_layout').delete()
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('ticketoutputpdf', '0002_auto_20180605_2022'),
+    ]
+
+    operations = [
+        migrations.RunPython(cleanup, migrations.RunPython.noop)
+    ]