Issue #3253, improve kubernetes-version error string

[flyingcircle]

Since the kubernetes version is used in creating the URLs to grab binaries, not including the 'v' would require adding it back in certain places. Simply adding a better error message.

[k8s-ci-robot]

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[minikube-bot]

Can one of the admins verify this patch?

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: flyingcircle
To fully approve this pull request, please assign additional approvers.
We suggest the following additional approver: dlorenc

If they are not already assigned, you can assign the PR to them by writing /assign @dlorenc in a comment when ready.

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[tstromberg]

@minikube-bot OK to test

[tstromberg]

Any chance of signing the CLA so that this could be merged?

📝 Instructions at https://git.k8s.io/community/CLA.md#the-contributor-license-agreement

[flyingcircle]

I signed it

[tstromberg]

The bot isn't noticing the CLA signing, and says "commit missing GitHub user"

c9d79f1 says the commit is by "Jeremy Hamilton" - which is presumably you, but perhaps with an e-mail address that doesn't match what GitHub has?

I found this article about the problem: https://help.github.com/en/articles/why-are-my-commits-linked-to-the-wrong-user

Do you mind checking it out? My apologies for the CLA headache.

[flyingcircle]

I've switched my email. I'll see if that fixes it (primary/secondary github email?). But everything matches.

[tstromberg]

c9d79f1 still says "Jeremy Hamilton" instead of "flyingcircle", so the CLA checker is still failing :(

[flyingcircle]

Alright that took far too long, just ended up having to rebase, and edit my local repo's commit history. But it all looks good now.

[tstromberg]

Thanks for seeing this one through! My apologies for the CLA being so difficult to get sorted out.