Empty trades

[samolego]

TraderNPCs/common/src/main/java/org/samo_lego/tradernpcs/profession/TraderNPCProfession.java

Line 62 in 8a23a28

if (!tradeStack1.isEmpty() || !tradeStack2.isEmpty() || !sellStack.isEmpty())

This allows for "half-empty" trades to be present, e.g. buying / selling air, which is silly.