message: fix mem leak on header
diff: @@ -216,9 +216,8 @@ pub struct CXResultIter<'a> {
  #[no_mangle]
  pub unsafe extern "C" fn free_result_iter<'a>(res: *const CXResultIter<'a>) {
  - let _ = get_vec::<_>((*res).header.ptr, (*res).header.len, (*res).header.capacity);
  - // should not need to free string if they are just pointing to the arrow_iter.dst
  - // header.into_iter().for_each(|col| free_str(col));
  + let header = get_vec::<_>((*res).header.ptr, (*res).header.len, (*res).header.capacity);
  + header.into_iter().for_each(|col| free_str(col));
  let arrow_iter = Box::from_raw(res as *mut CXResultIter<'a>);
  let _ = Box::from_raw(arrow_iter.iter);
  