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

fy = [fiscalyear_id]
            self.cr.execute("select id from account_period where fiscalyear_id = ANY(%s)", (fy,))
            periods = self.cr.fetchall()
            for p in periods:
                period_list.append(p[0])
            res = self._add_codes(based_on, res, period_list, context=context)
        i = 0
        top_result = []
        while i < len(res):
            res_dict = { 'code': res[i][1]['code'],
                'name': res[i][1]['name'],
                'debit': 0,
                'credit': 0,
                'tax_amount': res[i][1]['sum_period'],
                'type': 1,
                'level': res[i][0],
                'pos': 0
            }
            top_result.append(res_dict)
            res_general = self._get_general(res[i][1]['id'], period_list, company_id, based_on, context=context)
            ind_general = 0
            while ind_general < len(res_general):
                res_general[ind_general]['type'] = 2
                res_general[ind_general]['pos'] = 0
                res_general[ind_general]['level'] = res_dict['level']
                top_result.append(res_general[ind_general])
                ind_general+=1
            i+=1
        return top_result
    def _get_general(self, tax_code_id, period_list, company_id, based_on, context=None):