Automatic merge from submit-queue

Fixed incorrect result of getMinTolerationTime.

For the following case, `getMinTolerationTime` should return one; but  it returned -1 ：
1. for tolerations[0], TolerationSeconds is nil, minTolerationTime is not set 
2. for tolerations[1], it's TolerationSeconds (1) is bigger than `minTolerationTime`, so minTolerationTime is still -1 which means infinite.

```
+		{
+			tolerations: []v1.Toleration{
+				{
+					TolerationSeconds: nil,
+				},
+				{
+					TolerationSeconds: &one,
+				},
+			},
+		},
```