message: fix onChange for selectMenu when using tags
diff: @@ -365,7 +365,6 @@ export class SelectMenu extends React.Component<SelectMenuProps, SelectMenuState
  const key = _get(option, 'key', option);
  // @ts-ignore
  const isOptionSelected = Boolean(selectedOptions[key]);
  -
  let newSelectedOptions = isMultiSelect ? selectedOptions : {};
  if (isOptionSelected) {
  // @ts-ignore
  @@ -390,11 +389,20 @@ export class SelectMenu extends React.Component<SelectMenuProps, SelectMenuState
  handleRemoveOption = (option: SelectMenuItem) => {
  return () => {
  + const { isMultiSelect, onChange } = this.props;
  const { selectedOptions } = this.state;
  let newSelectedOptions = { ...selectedOptions };
  // @ts-ignore
  delete newSelectedOptions[_get(option, 'key', option)];
  this.setState({ selectedOptions: newSelectedOptions });
  + let newValues: SelectMenuItems | SelectMenuItem | null = Object.values(newSelectedOptions);
  + if (newValues.length === 0) {
  + newValues = null;
  + } else if (!isMultiSelect) {
  + newValues = newValues[0];
  + }
  + const value = _get(option, 'value', option);
  + onChange && onChange(value, option, newValues);
  };
  };
  