T7488: call utility to rollback vpp section of config after apply stage error

[jestabro]

Change Summary

This requires PR vyos/vyos-1x#4552 to be merged first.

Call rollback utility needed for VPP restart. It is a no-op if vpp is not configured.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Other (please describe):

Related Task(s)

Related PR(s)

vyos/vyos-1x#4552
vyos/vyos-vpp#34

Component(s) name

Proposed changes

How to test

Tested by @natali-rs1985 in the context of vyos/vyos-vpp#34

Smoketest result

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[dmbaturin]

This is a straightforward companion to the PR that adds a section rollback utility, no objections.

[sever-sever]

Checked, works as expected