BUG : Organization owners don't get the "Your app is ready for install" emails

Organization owners did not get the “Your app is ready for install” e-mails, because we added owner to “notify_email_list” only if the owner was a User, but not in case if the Owner was an Organization.

Now, if the owner of the app is an Organization then we will add all owners of the Organization to the “notify_email_list”.