Add dhiller to approvers

[dhiller]

What this PR does / why we need it: Add @dhiller to approvers

Does this PR fix any issue? _(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged)_:

Fixes #

Special notes for your reviewer: /cc @mazzystr

[kubevirt-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: To complete the pull request process, please assign mazzystr after the PR has been reviewed. You can assign the PR to them by writing /assign @mazzystr in a comment when ready.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files: - **[OWNERS](https://github.com/kubevirt/kubevirt.github.io/blob/master/OWNERS)** Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[kubevirt-bot]

The following users are mentioned in OWNERS file(s) but are untrusted for the following reasons. One way to make the user trusted is to add them as [members]() of the kubevirt org. You can then trigger verification by writing /verify-owners in a comment.

• stu-got
  • User is not a member of the org. User is not a collaborator. Satisfy at least one of these conditions to make the user trusted.

[kubevirt-bot]

@dhiller: The following test failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
kubevirt-io-presubmit-link-checker	492a02d03c814e8f1e1990e0e82408f86ea9efa7	link	/test kubevirt-io-presubmit-link-checker

Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository. I understand the commands that are listed [here](https://go.k8s.io/bot-commands).