function busyPortDialog (port, alt) {
  hideOtherWindows()
  const opt = showDialog({
    title: i18n.t('busyPortDialog.title'),
    message: i18n.t('busyPortDialog.message', { port, alt }),
    type: 'error',
    buttons: [
      i18n.t('busyPortDialog.action', { port, alt }),
      i18n.t('quit')
    ]
  })

  return opt === 0
}
Dialog to show when there is a busy port and we offer an alternative.

@param {Number} port is the busy port
@param {Number} alt is the alternative free port
@returns {boolean} use the alternative port