https://tc39.es/proposal-intl-datetime-style/ (Jun 10, 2020)

fix extra s in message

Bug: v8:10613
Change-Id: I2ef4f4004c1e8f0a58bf4409578876d1553de59b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2242258
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68329}