crypto-square: fix tests not comparing actual to expected

[glennj]

The current tests do not actually test anything. Problem exposed during a mentoring session.

The example needed updating to pass the tests.

[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

If this PR does not affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), please add the following to the merge-commit message which will stops student's tests from re-running. Please copy-paste to avoid typos.

[no important files changed]

For more information, refer to the documentation. If you are unsure whether to add the message or not, please ping @exercism/maintainers-admin in a comment. Thank you!

[iHiD]

You able to merge @glennj ?

[glennj]

You able to merge ?

@iHiD No, not a Lua team member.

[glennj]

This PR definitely does affect the result of the test. [no important files changed] DOES NOT APPLY.

However, only 61 starts and 32 completions of this, so not a heavy burden to retest them all.

[iHiD]

@iHiD No, not a Lua team member.

@glennj Lies 😉

[ryanplusplus]

Thanks!