tryReadTBQueueDefault: fix bug when returning Nothing
#702
| Job | Run time |
|---|---|
| 4m 38s | |
| 17m 4s | |
| 7m 42s | |
| 5m 7s | |
| 4m 11s | |
| 7m 55s | |
| 5m 21s | |
| 4m 42s | |
| 6m 33s | |
| 5m 8s | |
| 4m 52s | |
| 7m 20s | |
| 5m 29s | |
| 4m 50s | |
| 7m 53s | |
| 3m 10s | |
| 5m 6s | |
| 11m 54s | |
| 1h 58m 55s |