message: Fix SimpleConsensus test: take new timestamp rule into account.
diff: @@ -246,7 +246,7 @@ fn simple_consensus() {
  let hash1 = proposal1.hash();
  let proposal2 = Proposal {
  - timestamp,
  + timestamp: timestamp + sc_c.params.min_round_length(),
  maybe_block: Some(new_payload(true)),
  maybe_parent_round_id: Some(1),
  };
  