Long processing when validating an statement with so much lines that pay the same invoice
The validation of a statement with 34 lines that pay a single invoice producess an infinite loop. This is caused to the call to `invoice.get_reconcile_lines_for_amount` which calls a [combination method](https://foss.heptapod.net/tryton/tryton/-/blob/branch/default/modules/account_invoice/invoice.py#L1537) that is exponential. When the number of lines to reconciles is big, the time it takes to process all the combinations blocks the server.
issue