OpenShift 4 update fails with "It may not be safe to apply this update"

Issue

Can't upgrade OpenShift cluster from 4.6.z to 4.7.z

  - lastTransitionTime: '2021-03-17T09:25:44Z'
    message: 'Unable to apply 4.7.1: it may not be safe to apply this update'
    reason: UpgradePreconditionCheckFailed
    status: 'True'
    type: Progressing


  - lastTransitionTime: '2021-03-17T12:23:13Z'
    message: 'Precondition "ClusterVersionUpgradeable" failed because of "CertRotationTime_CertRotationBaseOverridden":
      Cluster operator kube-apiserver cannot be upgraded between minor versions: CertRotationTimeUpgradeable:
      configmap["openshift-config"]/unsupported-cert-rotation-config .data["base"]=="9000s"'
    reason: UpgradePreconditionCheckFailed
    status: 'True'
    type: Failing