fix: use old email to build reset_url on email change (#4278)

Co-authored-by: Julie Rymer <jrymer@biru.sh>

src/oscar/apps/customer/views.py

@@ -347,7 +347,7 @@ def send_email_changed_email(self, old_user, new_email):
         user = self.request.user
         extra_context = {
             "user": user,
-            "reset_url": get_password_reset_url(old_user),
+            "reset_url": get_password_reset_url(user),
             "new_email": new_email,
             "request": self.request,
         }