Impacted versions: 9.0, 9.0 enterprise

Steps to reproduce:
On current runbot duplicate any posted journal entry which is balanced

Current behavior:
Error message "Cannot create unbalanced entry" is shown

Expected behavior:
New Journal entry is created in state 'draft'

Video/Screenshot link (optional):
![selection_268](https://cloud.githubusercontent.com/assets/14974044/15007437/41f45a56-11d9-11e6-84f3-b297befaa521.png)

if type == t:
                        ok = True
                        break
            if journal.account_control_ids and not ok:
                for a in journal.account_control_ids:
                    if a.id == vals['account_id']:
                        ok = True
                        break
            
            
            if account.currency_id and 'amount_currency' not in vals and account.currency_id.id != account.company_id.currency_id.id:
                vals['currency_id'] = account.currency_id.id
                ctx = {}
                if 'date' in vals:
                    ctx['date'] = vals['date']
                vals['amount_currency'] = account.company_id.currency_id.with_context(ctx).compute(amount, account.currency_id)
        if not ok:
            raise UserError(_('You cannot use this general account in this journal, check the tab \'Entry Controls\' on the related journal.'))
        
        tax_lines_vals = []
        if apply_taxes and not context.get('dont_create_taxes') and vals.get('tax_ids'):
            
            tax_ids = [tax['id'] for tax in self.resolve_2many_commands('tax_ids', vals['tax_ids']) if tax.get('id')]
            
            taxes = self.env['account.tax'].browse(tax_ids)
            currency = self.env['res.currency'].browse(vals.get('currency_id'))
            partner = self.env['res.partner'].browse(vals.get('partner_id'))
            res = taxes.compute_all(amount,
                currency, 1, vals.get('product_id'), partner)