Fix syntax in mysql setup documentation (#24893

[nigel-millward]

In the 'set-up-databases' documentation the code block was not working on newer versions of mssql. Updated the docs so that the query works on supported 2017 and 2019 versions of mssql

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^ Add meaningful description above

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[boring-cyborg]

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[boring-cyborg]

Awesome work, congrats on your first merged pull request!

[jedcunningham]

Thanks @nigel-millward! Congrats on your first commit!