added OCP version check to check routine of #247

[knumskull]

Description

With this check, it's not possible to install an OCP cluster using IPv6, regardless which version is selected.

With this PR, an version_check is added to allow installations with OCP < 4.12

TASK [Check IPv6 & OpenShift 4.12] *********************************************                                      
fatal: [host]: FAILED! => {"changed": false, "msg": "Currently, it is not possible to install OpenShift 4.12 with IPv6
 enabled with hetzner-ocp4 because of Issue #247"}      

Checklist/ToDo's

• [ ] Added documentation?
• [ ] Added release note entry? ( docs/release-notes.md )
• [X] Tested?

[rbo]

/ok-to-test

[rbo]

Good point

[rbo]

Thanks for your contribution, merged into devel