Merge pull request #35700 from mmilata/bump-pflag

Automatic merge from submit-queue

Update github.com/spf13/pflag to latest version

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**What this PR does / why we need it**:
This PR updates `github.com/spf13/pflag` to the latest version.

* OpenShift needs pflag bump in order to use [`StringArray`](spf13/pflag#89), and
* Latest revision contains couple of bugfixes that I'd like to have there, and
* Kubernetes should have the same version, which is the reason for this PR

**Which issue this PR fixes**:
None, related to openshift/origin#11539.

**Special notes for your reviewer**:
`hack/verify-godeps.sh` fails with following output even though I haven't touched that package: https://gist.github.com/mmilata/3cb84b754f9b9e7ff371a7b6c5131b09

Am I using the wrong golang/godep version perhaps? Any hint what am I doing wrong?
**Release note**:
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```release-note
NONE
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Author: Kubernetes Submit Queue