🐛 Fix panic executing manager without valid kube context

[mdbooth]

Fixes #2054

/hold

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[EmilienM]

/lgtm

[EmilienM]

/hold cancel

[jichenjc]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jichenjc

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[kashifest]

How about cherry-pick to release branch ?

[EmilienM]

/cherry-pick release-0.10

[k8s-infra-cherrypick-robot]

@EmilienM: new pull request created: #2061

In response to this:

/cherry-pick release-0.10

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