message: Remove redundant CRLF for empty header set
diff: @@ -158,9 +158,6 @@ impl Headers {
  buf.extend_from_slice(b"\r\n");
  }
  }
  - if self.inner.is_empty() {
  - buf.extend_from_slice(b"\r\n");
  - }
  buf.extend_from_slice(b"\r\n");
  buf
  }
  