Fix document about StringQuery.

[matumu]

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Closes #2204

[sothawo]

Thanks for finding and fixing this. Please create an issue for this and reference this issue with the "Closes #issue-number" min your pull request - we don't commit code without this.

[matumu]

Thanks for finding and fixing this. Please create an issue for this and reference this issue with the "Closes #issue-number" min your pull request - we don't commit code without this.

👌