cli: don't show password in \c metacommand

[rafiss]

fixes #87294

Release note (cli change): The \c metacommand no longer shows the
password in plaintext.

Release justification: low risk change

[cockroach-teamcity]

This change is 

[knz]

nice

Reviewed 3 of 3 files at r1, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @rafiss)

[rafiss]

tftr!

bors r=knz

[craig]

This PR was included in a batch that successfully built, but then failed to merge into master. It will not be retried.

Additional information:

{"message":"1 review requesting changes by reviewers with write access.","documentation_url":"https://docs.github.com/articles/about-protected-branches"}

[rafiss]

bors r=knz

[craig]

Build failed (retrying...):

• Bazel Essential CI (Cockroach)

[craig]

Build failed (retrying...):

• Bazel Essential CI (Cockroach)

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)

[blathers-crl]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

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error creating merge commit from 887e4d9 to blathers/backport-release-21.2-87298: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 21.2.x failed. See errors above.

---

error creating merge commit from 887e4d9 to blathers/backport-release-22.1-87298: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 22.1.x failed. See errors above.

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