[FIX] payment: fix custom payment.transaction create method mechanism

This commit will correctly check for a custom payment.transaction create method
on 'self' instead of the acquirer's provider before calling it.

closes odoo/odoo#33033

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/payment/models/payment_acquirer.py

@@ -490,7 +490,7 @@ class PaymentTransaction(models.Model):
 
             # custom create
             custom_method_name = '%s_create' % acquirer.provider
-            if hasattr(acquirer, custom_method_name):
+            if hasattr(self, custom_method_name):
                 values.update(getattr(self, custom_method_name)(values))
 
         # Default value of reference is