message: Fix bug in Ell::read()
diff: @@ -69,6 +69,7 @@ size_type calculate_max_nonzeros_per_row(
  size_type max_nonzeros_per_row = 0;
  for (const auto &elem : data.nonzeros) {
  if (elem.row != current_row) {
  + current_row = elem.row;
  max_nonzeros_per_row = std::max(max_nonzeros_per_row, nnz);
  nnz = 0;
  }
  