Empty messages result in weird push notifications
See https://github.com/mattermost/mattermost-webapp/blob/149cb00b8282fbf3c31a82ed31b1be4d0b660883/actions/notification_actions.jsx#L155, the push notification contents are mysteriously "@botname did something new", thought it was somehow coming from OpenAI for a good while! Ideally we should wait a while so there is already some actual content to post when the reply is first created.