89c1491d35 wallet: if only have one output type, don't perform "mixed" coin selection (furszy)
Pull request description:
For wallets that only have one output type, we are currently performing the same
selection process over the same coins twice.
The "mixed coin selection" doesn't add any value to the result
(there is nothing to mix if the available coins struct has only one type).
ACKs for top commit:
achow101:
ACK 89c1491d35
john-moffett:
ACK 89c1491d35
kristapsk:
cr utACK 89c1491d35
Tree-SHA512: 672eaeed3ba911d13fa61a46f719c8fe1ebe4d2dc7d723040e71937c693659411bc99cdbd9f0014e836b70eebeff1b8ca861f4d81d39e6f79f437364a526edbe