Fixed slow-running external request test
Fixed slow-running external request test

refs https://github.com/TryGhost/Team/issues/860

- Slow unit tests cause longer waiting time to deliver code to main. Before this fix the test was taking a whooping 6s on average
- The main cause of the delay was a downstream's package (got) default retry logic that was taking up a lot of time. The test is meant to check a "500" response handling not a retry logic, so disabling it for this specific test makes sense

janvt/Ghost,ErisDS/Ghost,ErisDS/Ghost,TryGhost/Ghost,ErisDS/Ghost,e10/Ghost,TryGhost/Ghost,e10/Ghost,TryGhost/Ghost,janvt/Ghost