message: Use the proper error type on u64 overflow
diff: @@ -77,7 +77,7 @@ impl FieldType {
  Ok(Value::U64(field_val_u64))
  }
  else {
  - Err(ValueParsingError::TypeError(format!("Expected an u64 int, got {:?}", json)))
  + Err(ValueParsingError::OverflowError(format!("Expected an u64 int, got {:?}", json)))
  }
  }
  FieldType::Str(_) => {
  