Very minor grammar fix in error message
minor #13036 [Config] Very minor grammar fix in error message (WouterJ)

This PR was merged into the 2.3 branch.

Discussion
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[Config] Very minor grammar fix in error message

It's just a tiny detail, but I found it important enough to submit a fix.

| Q   | A
| --- | ---
| License | MIT
| Fixed tickets | -

Commits
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1c65f36 Very minor grammar fix in error message
fixed CS