issueasset: issuance is always blinded

[delta1]

Expected behavior

calling issueasset with blind=false should create an explicit (unblinded) issuance

Actual behavior

issuance is always blinded

To reproduce

issueasset 100 1 false

[afeezaziz]

I was thinking, on top of this, is it possible to have non-confidential / non-blinded transaction as default? It would be cheaper.

[apoelstra]

No, we should not default to making less-private transactions.

Separately we are looking into fixing the cost incentives around CT though -- it shouldn't be cheaper to harm everyone's privacy!