message: set key of filtered item
diff: @@ -1052,7 +1052,7 @@ class Select extends React.Component {
  if (inputValue && this.filterOption(inputValue, child)) {
  const innerItems = childrenToArray(child.props.children).map(subChild => {
  const childValue = getValuePropValue(subChild);
  - return <MenuItem key={childValue} {...subChild.props} />;
  + return <MenuItem key={childValue || subChild.key} {...subChild.props} />;
  });
  sel.push(
  