I submitted a PR that should fix this as soon as the translations are pushed to Transifex.
https://github.com/discourse/discourse/pull/3574
BTW: Should the following keys be pluralized too?
https://github.com/gschlager/discourse/blob/patch-2/plugins/poll/config/locales/client.en.yml#L30-L34
If I’m not mistaken count will never be 1 for those keys, so the missing pluralization doesn’t matter for languages like English or German. But I imagine it could be a problem for languages like Russian…
I messaged the Transifex support and asked if they can change the algorithm that detects pluralization to support the special case of “zero”. If they can’t do that we’d need to rename all “zero” keys in the locale files and change the calls to I18n.t for those keys… There’s only one “many” key in the locale files and that’s a valid one.