Bug 1013295 - [Messages] Migrated messages do not have a proper sentTimestamp. Hiding label with invalid timestamp. r=schung
Merge pull request #19556 from azasypkin/v1.4-bug-1013295-invalid-timestamp

 Bug 1013295 - [Messages] Migrated messages do not have a proper sentTimestamp. Hiding label with invalid timestamp. r=schung