Fix typo. Closes T8915.

Summary:
From 'or' to 'are'.
Closes T8915.

Test Plan: Wait 30 seconds.

Reviewers: joshuaspence, Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T8915

Differential Revision: https://secure.phabricator.com/D13664