Update videofile key on model

courses/migrations/0031_auto_20210726_1523.py

+# Generated by Django 2.2.24 on 2021-07-26 18:23
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('courses', '0030_videofile'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='videofile',
+            name='video',
+            field=models.OneToOneField(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='file', to='courses.Video', verbose_name='file'),
+        ),
+    ]