message: Fix evidence validation
diff: @@ -328,7 +328,7 @@ impl<C: Context> Highway<C> {
  }
  Vertex::Evidence(evidence) => {
  evidence.validate()?;
  - if self.validators.contains(evidence.perpetrator()) {
  + if !self.validators.contains(evidence.perpetrator()) {
  return Err(EvidenceError::UnknownPerpetrator.into());
  }
  Ok(())
  