message: Make postgres protocol version value more readable
diff: @@ -260,7 +260,8 @@ where
  I: IntoIterator<Item = (&'a str, &'a str)>,
  {
  write_body(buf, |buf| {
  - buf.put_i32(196_608);
  + // postgres protocol version 3.0(196608) in bigger-endian
  + buf.put_i32(0x00_03_00_00);
  for (key, value) in parameters {
  write_cstr(key.as_bytes(), buf)?;
  write_cstr(value.as_bytes(), buf)?;
  