ContractorSynchronizer: set tax ID type on contractor

 src/ContractorSynchronizer.php

@@ -48,6 +48,7 @@

        if ($contractor->nip() != $client['companyTaxId']) {
            $changed = TRUE;
            $contractor->changeTaxId(Contractors\TaxIdType::nip());
            $contractor->changeNip($client['companyTaxId']);
        }