message: Remove redundant information from error message
diff: @@ -74,18 +74,9 @@ fn test() {
  Some(ProtocolOutcome::InvalidIncomingMessage(invalid_msg, offending_sender, _err)) => {
  assert_eq!(
  invalid_msg, &msg,
  - "Invalid message is not message that was sent.\
  - Invalid message in protocol outcome: {:?} ;\
  - Message that was sent: {:?}",
  - invalid_msg, &msg
  + "Invalid message is not message that was sent."
  );
  - assert_eq!(
  - offending_sender, &sender,
  - "Unexpected sender.\
  - Sender according to protocol outcome: {:?} ;\
  - message that was sent: {:?}",
  - offending_sender, &sender
  - )
  + assert_eq!(offending_sender, &sender, "Unexpected sender.")
  }
  Some(protocol_outcome) => panic!("Unexpected protocol outcome {:?}", protocol_outcome),
  }
  