Add migration for new rule.

src/paperless_mail/migrations/0015_alter_mailrule_action.py

@@ -0,0 +1,28 @@
+# Generated by Django 4.0.4 on 2022-05-29 13:21
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("paperless_mail", "0014_alter_mailrule_action"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="mailrule",
+            name="action",
+            field=models.PositiveIntegerField(
+                choices=[
+                    (1, "Delete"),
+                    (2, "Move to specified folder"),
+                    (3, "Mark as read, don't process read mails"),
+                    (4, "Flag the mail, don't process flagged mails"),
+                    (5, "Tag the mail with specified tag, don't process tagged mails"),
+                ],
+                default=3,
+                verbose_name="action",
+            ),
+        ),
+    ]