Update `Bengali` translation

Currently translated at 84.0% (517 of 615 strings)

Translation: Wiki-Bot/Discord
Translate-URL: https://translate.wikibot.de/projects/wiki-bot/discord/bn/

i18n/bn.json

@@ -138,7 +138,7 @@
         "votes": "$1 {{PLURAL:$2|ভোট|টি ভোট}} ($3%)"
     },
     "fallback": [
-        " ",
+        "en",
         " ",
         " ",
         " ",