[FIX] product: Change public pricelist currency when changing main currency

What are the steps to reproduce your issue ?

    1. Go to 'odoo.com/trial' and create a database with 'account'

    or

    1. Start local server with a new database and with '--without-demo=all --init=account'

    2. Change main currency from 'EUR' to 'USD' in settings

What is currently happening?

    Error raised when trying to install 'point_of_sale'

What are you expecting to happen?

    Install 'point_of_sale' normally even after changing main currency

Why is this happening?

    But there is a condition which verifies that there is not already
    a pricelist with the currency we want to set or with the currency
    of the company. Otherwise it prevents the pricelist modification

How to fix the bug ?

    Change the condition so that it allows the change of the pricelist
    in the case where the currency we want to set is not the same as the
    currency of the company

opw-2376457

closes odoo/odoo#61764

Signed-off-by: Achraf <abz-odoo@users.noreply.github.com>