Privacy Levels: migrate protected projects to private

All protected projects should be private for .org and .com.
Next step is to send an email to all .org users that have private
projects.

readthedocs/projects/migrations/0066_migrate_protected_projects.py

@@ -0,0 +1,24 @@
+# Generated by Django 2.2.16 on 2020-10-27 15:00
+
+from django.db import migrations
+
+
+def forwards_func(apps, schema_editor):
+    """Migrate all protected projects to private."""
+    Project = apps.get_model('projects', 'Project')
+    (
+        Project.objects
+        .filter(privacy_level='protected')
+        .update(privacy_level='private')
+    )
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('projects', '0065_add_feature_future_default_true'),
+    ]
+
+    operations = [
+        migrations.RunPython(forwards_func),
+    ]