Do not redirect to unmaintained translations

Do not automatically redirect from /index.html to unmaintained
or outdated translations. Currently this affects pl, tr.

Related to ruby#1828.

Author: stomar

index.html

@@ -13,10 +13,8 @@
         "it":    "it",
         "ja":    "ja",
         "ko":    "ko",
-        "pl":    "pl",
         "pt":    "pt",
         "ru":    "ru",
-        "tr":    "tr",
         "vi":    "vi",
         "zh-CN": "zh_cn",
         "zh-TW": "zh_tw"