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)

""" After running the manual reconciliation wizard and making full reconciliation, we need to run this method to create
            potentially an exchange rate entry that will balance the remaining amount_residual_currency (possibly several aml).
            This ensure that all aml in the full reconciliation are reconciled (amount_residual = amount_residual_currency = 0).
        """
        total_amount_currency = 0
        currency = False
        aml_to_balance_currency = self.env['account.move.line']
        maxdate = None
        for aml in self:
            if aml.amount_residual_currency:
                aml_to_balance_currency |= aml
            maxdate = max(aml.date, maxdate)
            if not currency and aml.currency_id:
                currency = aml.currency_id
            if aml.currency_id and aml.currency_id == currency:
                total_amount_currency += aml.amount_currency
        if currency and aml_to_balance_currency:
            aml = aml_to_balance_currency
            
            partial_rec = aml.credit and aml.matched_debit_ids[0] or aml.matched_credit_ids[0]
            aml_id, partial_rec_id = partial_rec.create_exchange_rate_entry(aml, 0.0, total_amount_currency, currency, maxdate)
    @api.multi
    def remove_move_reconcile(self):