message: fix: witness loading logic
diff: @@ -30,7 +30,8 @@ impl<'a> LoadWitness<'a> {
  .group_inputs
  .get(index)
  .and_then(|actual_index| self.witnesses.get(*actual_index).cloned()),
  - _ => self.witnesses.get(index).cloned(),
  + Source::Transaction(SourceEntry::Input) => self.witnesses.get(index).cloned(),
  + _ => None,
  }
  }
  }
  