Update outdated slugs for existing products

Our previous method of slug generation did not account for ID verification. This change allows us to correct the structure of existing slugs during migration.

ecommerce/courses/models.py

@@ -139,6 +139,8 @@ class Course(models.Model):
 
         try:
             seat = Product.objects.get(slug__in=slugs)
+            seat.slug = slug
+
             logger.info(
                 'Retrieved course seat child product with certificate type [%s] for [%s] from database.',
                 certificate_type,