Bithumb - Do not call place order for less than minimum order size

[sjanel]

If Bithumb round down the amount, coincenter makes another call with a lower amount. This amount can reach 0:

[2023-05-12 08:56:20.705] [info] POST https://api.bithumb.com/trade/place?endpoint=%2Ftrade%2Fplace&order_currency=XRP&payment_currency=KRW&type=ask&price=577.2&units=0.000091
[2023-05-12 08:56:21.146] [warning] Bithumb told us that number of decimals is 4
[2023-05-12 08:56:21.146] [info] POST https://api.bithumb.com/trade/place?endpoint=%2Ftrade%2Fplace&order_currency=XRP&payment_currency=KRW&type=ask&price=577.2&units=0
terminate called after throwing an instance of 'cct::exception'
  what():  Bithumb error 5500
[2023-05-12 08:56:21.452] [Aborted

We should not call place order at this step.