[SECURITY] Bind relevant cached file downloads to the current session

src/pretix/base/migrations/0174_auto_20201218_1810.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.0.11 on 2020-12-18 18:10
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0173_auto_20201211_1648'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='cachedfile',
+            name='session_key',
+            field=models.TextField(null=True),
+        ),
+        migrations.AddField(
+            model_name='cachedfile',
+            name='web_download',
+            field=models.BooleanField(default=True),
+        ),
+    ]