Impacted versions:
- 8.0

Steps to reproduce:
1. open Accounting / Configuration / Taxes / Tax Codes
2. open any Tax Code
3. press Print / Account Tax

Current behavior:

QWebException: "chart_tax_id" while evaluating
"get_lines(data['form']['based_on'], data['form']['company_id'], data['form']['chart_tax_id'])"
Details: http://paste.ubuntu.com/12689915/

Expected behavior:
- Tax Code report

Test on:
- different 8.0 instances
- runbot: http://105817-8-0-6b6d73.runbot8.odoo.com/web

addons/account/report/report_vat.py
if (account_elem['level'] < old_level):
                bcl_current_level = old_level
                bcl_rup_ind = ind - 1
                while (bcl_current_level >= int(accounts[bcl_rup_ind]['level']) and bcl_rup_ind >= 0 ):
                    res_tot = { 'code': accounts[bcl_rup_ind]['code'],
                        'name': '',
                        'debit': 0,
                        'credit': 0,
                        'tax_amount': accounts[bcl_rup_ind]['tax_amount'],
                        'type': accounts[bcl_rup_ind]['type'],
                        'level': 0,
                        'pos': 0
                    }
                    if res_tot['type'] == 1:
                        
                        res_tot['type'] = 2
                        result_accounts.append(res_tot)
                    bcl_current_level =  accounts[bcl_rup_ind]['level']
                    bcl_rup_ind -= 1
            old_level = account_elem['level']
            result_accounts.append(account_elem)
            ind+=1
        return result_accounts
class report_vat(osv.AbstractModel):
    _name = 'report.account.report_vat'
    _inherit = 'report.abstract_report'
    _template = 'account.report_vat'
    _wrapped_report_class = tax_report