message: Changed the implementation of how previously shown notifications get detected
  Previously the deduplication was only detected if it was the same notification was the immidiate predecessor.
diff: @@ -118,11 +118,12 @@ exports.sendNotification = function (challenge, isRestore) {
  hidden: !config.get('application.showChallengeSolvedNotifications'),
  isRestore: isRestore
  }
  + const wasPreviouslyShown = notifications.find(({key}) => key === challenge.key) !== undefined
  notifications.push(notification)
  - if (global.io && prevChallengeKey !== challenge.key) {
  +
  + if (global.io && (isRestore || wasPreviouslyShown)) {
  global.io.emit('challenge solved', notification)
  }
  - prevChallengeKey = challenge.key
  }
  }
  