Backport of Show no config warning error bug fix into release/1.9.x

[hc-github-team-secure-vault-core]

Backport

This PR is auto-generated from #14808 to be assessed for backporting due to the inclusion of the label backport/1.9.x.

WARNING automatic cherry-pick of commits failed. Commits will require human attention.

The below text is copied from the body of the original PR.

---

This PR correctly set the conditional to only show this warning at the right time, but something with mountModel always returned false when called before the save.

I also fixed a test that should have been catching this 🤦🏻‍♀️ (a test I wrote and incorrectly used ok when I should have been checking for the text).

[hashicorp-cla]

Thank you for your submission! We require that all contributors sign our Contributor License Agreement ("CLA") before we can accept the contribution. Read and sign the agreement

Learn more about why HashiCorp requires a CLA and what the CLA includes

---

1 out of 2 committers have signed the CLA.

• Monkeychip
• temp

---

temp seems not to be a GitHub user.
You need a GitHub account to be able to sign the CLA. If you already have a GitHub account, please add the email address used for this commit to your account.

_{Have you signed the CLA already but the status is still pending? Recheck it.}