🐛Attendees cannot buy ticket from 2 separate organizers using the same email.

[meilechwieder]

Describe the bug
Attendees cannot buy ticket from 2 separate organizers using the same email.

To Reproduce
Steps to reproduce the behavior:

1. create 2 organizers account
2. for each, create an event and a ticket
3. buy a ticket from organizer1 with email@email.com
4. try to buy a ticket from organizer2 with email@email.com
5. proceed to payment - you'll see credit card form will not load

Expected behavior
user should be able to checkout and pay for his ticket on organizer2's event

Hi.Events Version and platform
Tested on local

[meilechwieder]

We can fix this by adding a stripe_account_id column in the stripe_customers table, and passing in the stripe_acccount_id when creating the stripe_customer. Also, in the stripeCustomerUpsert, we would have to search by email and stripe_account_id, not only by email