Fix typo in enable spelling

[btrieger]

What this PR does / why we need it

Which issue(s) this PR fixes

Fix typo in enable in error message about legacy cluster config

Fixes #

Describe testing done for PR

NA as it was a typo

Release note

Additional information

Special notes for your reviewer

[github-actions[bot]]

Hi @btrieger! And thank you for opening your first Pull Request. Someone will review it soon. Thank you for committing to making Tanzu Framework better.

[github-actions[bot]]

Cluster Generation A/B Results: https://storage.googleapis.com/tkg-clustergen/4342/20230208195852/clustergen.diff.txt Author/reviewers: Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.