message: restore the HasHeader too
diff: @@ -217,6 +217,13 @@ impl property::HasMessages for Block {
  }
  }
  +impl property::HasHeader for Block {
  + type Header = Header;
  + fn header(&self) -> Self::Header {
  + self.header.clone()
  + }
  +}
  +
  #[cfg(test)]
  mod test {
  