[csharp][generichost] Fix format string parameter (#22282)

[macmanad]

Fixes #22282 Fix format string parameter referencing index not present in params
@mandrean @shibayan @Blackclaws @lucamazzanti @iBicha

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[wing328]

Thanks for the PR but your commit (as shown in the Commits tab) is not linked to your Github account, which means this PR won't count as your contribution in https://github.com/OpenAPITools/openapi-generator/graphs/contributors.

Let me know if you need help fixing it.

Ref: https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-can-i-update-commits-that-are-not-linked-to-my-github-account

[macmanad]

Thanks for the PR but your commit (as shown in the Commits tab) is not linked to your Github account, which means this PR won't count as your contribution in https://github.com/OpenAPITools/openapi-generator/graphs/contributors.

Let me know if you need help fixing it.

Ref: https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-can-i-update-commits-that-are-not-linked-to-my-github-account

That's fine, it's just a one character change to a format string, not exactly career defining

[macmanad]

Added email as secondary

[wing328]

cc @devhl-labs

[devhl-labs]

I am very confused how it became wrong, no one else mentioned it, and i don't see an issue. Looks good though.