update machine controller openstack rhel image

[moadqassem]

What this PR does / why we need it:
The current RHEL image on Openstack is RHEL 8.0 which had few issues. This PR updates the RHEL 8 image to the latest(8.5)

Which issue(s) this PR fixes (optional, in fixes #<issue number> format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

Optional Release Note:

NONE

[xrstf]

/override pull-machine-controller-e2e-vsphere
/override pull-machine-controller-e2e-vsphere-resource-pool

vCenter is offline.

[kubermatic-bot]

@xrstf: Overrode contexts on behalf of xrstf: pull-machine-controller-e2e-vsphere, pull-machine-controller-e2e-vsphere-resource-pool

In response to this:

/override pull-machine-controller-e2e-vsphere
/override pull-machine-controller-e2e-vsphere-resource-pool

vCenter is offline.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[xrstf]

/approve

[kubermatic-bot]

LGTM label has been added.

Git tree hash: d2683b9eeca6d7f0e654c1af436e585d8798505a

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: moadqassem, xrstf

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [moadqassem,xrstf]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[xrstf]

/retest