[FIX] l10n_it_edi: create 0% EU tax with correct exoneration values

When creating a new company with the italian fiscal localization, the
tax "0% EU" is not instanciated properly

Steps to reproduce:
1. Install Accounting and module l10n_it_edi
2. Create a new company and select it
3. Go to Settings > Accounting > Fiscal Localization, set it to `Italy -
   Generic Chart of Accounts` and save
4. Go to Accounting > Configuration > Taxes and open tax "0% EU"
5. The fields for the italian exoneration are not properly set, they
   should have the same values as the same tax for company "IT Company"
   of the demo data

Solution:
When we set the company chart template, update tax "0% EU" with the
correct values

opw-3414593

closes odoo/odoo#131996

Signed-off-by: Olivier Colson (oco) <oco@odoo.com>