l10n: Fix Japanese translation (#3410)

* "メデイア" -> "メディア"

Signed-off-by: lindwurm <lindwurm.q@gmail.com>

app/javascript/mastodon/locales/ja.json

@@ -146,7 +146,7 @@
   "status.delete": "削除",
   "status.favourite": "お気に入り",
   "status.load_more": "もっと見る",
-  "status.media_hidden": "非表示のメデイア",
+  "status.media_hidden": "非表示のメディア",
   "status.mention": "返信",
   "status.mute_conversation": "会話をミュート",
   "status.open": "詳細を表示",