Fix cannot peak job from the v2 engine if it's sinked into the secondary storage (#215)

Author: Napoleon0621

engine/redis_v2/engine.go

@@ -218,9 +218,6 @@ func (e *Engine) Peek(namespace, queue, optionalJobID string) (job engine.Job, e
 		}
 		body = res[0].Body()
 	}
-	if err != nil {
-		return nil, err
-	}
 	data := &model.JobData{}
 	if err = proto.Unmarshal(body, data); err != nil {
 		return nil, err

engine/redis_v2/engine_test.go

@@ -394,7 +394,7 @@ func TestEngine_Peek_SecondaryStorage(t *testing.T) {
 		ID:         "",
 		Body:       body,
 		TTL:        120,
-		Delay:      15,
+		Delay:      45,
 		Tries:      1,
 		Attributes: attributes,
 	})