Remove TariffChangeRequiredParamsError

The method "update_product" can be used also for just removing bonds, without the need to add any new product or additional bond.

We get this error when we are trying to change a tariff removing a bond, which we must avoid:

TariffChangeRequiredParamsError('Missing or empty required attributes for the requested one shot additional bond: additional_bonds

Moreover, here we decided to remove the whole exception instead of relaxing its restrictions. This exception might be too defensive, if some main parameter (asset_id, transaction_id) is missing the call with MM will fail and we'll get the error.