Update translation files

Updated by "Remove blank strings" hook in Weblate.

Translation: Soapbox/Soapbox
Translate-URL: https://hosted.weblate.org/projects/soapbox-pub/soapbox/

src/locales/ja.json

@@ -200,7 +200,6 @@
   "bundle_column_error.body": "ページの読み込み中に異常が発生しました。",
   "bundle_column_error.retry": "やり直す",
   "bundle_column_error.title": "ネットワークエラー",
-  "card.back.label": "",
   "chat.actions.send": "送信",
   "chat.failed_to_send": "メッセージの送信に失敗しました。",
   "chat.input.placeholder": "メッセージを入力",
@@ -1015,7 +1014,6 @@
   "poll.total_people": "{count, plural, one {# person} other {# people}}",
   "poll.total_votes": "{count}票",
   "poll.vote": "投票",
-  "poll.voted": "",
   "poll.votes": "{votes, plural, one {# vote} other {# votes}}",
   "poll_button.add_poll": "アンケートを追加",
   "poll_button.remove_poll": "アンケートを削除",