remove redundant 'solved' from ProduceSignature

[fivepiece]

We only enter the if blocks if solved is true.
The && inside seems redundant

[promag]

Introduced in #8149 by @sipa, it is indeed unnecessary. No harm keeping them though.

utACK 5579bb1.

[Empact]

It's slightly protective in that it guards against the unintentional introduction of a new case that overwrites a false solved. assert could be more helpful if we want to continue to guard against that though.

[laanwj]

No harm keeping them though.

It's slightly protective in that it guards against the unintentional introduction of a new case that overwrites a false solved

Meh. Tend towards NACK, I see no strong need to change this code, sorry.

[jonasschnelli]

Agree with @laanwj and @Empact.