[FIX] portal: fix new api forward-port migration

_create_user was called on self instead of wizard_user
(for wizard_user in self...)

This created an ensure_one crash later on if more than one record in self.

addons/portal/wizard/portal_wizard.py

@@ -138,7 +138,7 @@ class PortalWizardUser(models.TransientModel):
                 # create a user if necessary, and make sure it is in the portal group
                 if not user:
                     company_id = wizard_user.partner_id.company_id.id
-                    user_portal = self.sudo().with_context(company_id=company_id)._create_user()
+                    user_portal = wizard_user.sudo().with_context(company_id=company_id)._create_user()
                 else:
                     user_portal = user
                 wizard_user.write({'user_id': user_portal.id})