Use BigAutoField also in last migration

aleksis/core/migrations/0016_taskuserassignment.py

@@ -19,7 +19,7 @@ class Migration(migrations.Migration):
         migrations.CreateModel(
             name='TaskUserAssignment',
             fields=[
-                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('extended_data', models.JSONField(default=dict, editable=False)),
                 ('site', models.ForeignKey(default=1, editable=False, on_delete=django.db.models.deletion.CASCADE, to='sites.site')),
                 ('task_result', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='django_celery_results.taskresult', verbose_name='Task result')),