Redirect simple to en-simple

Addresses downstream bug
https://phabricator.wikimedia.org/T210840

data/langdb.yaml

@@ -150,6 +150,7 @@ languages:
   eml: [Latn, [EU], emiliàn e rumagnòl]
   en-ca: [Latn, [AM], Canadian English]
   en-gb: [Latn, [EU, AS, PA], British English]
+  en-simple: [Latn, [WW], Simple English]
   en: [Latn, [EU, AM, AF, ME, AS, PA, WW], English]
   eo: [Latn, [WW], Esperanto]
   es-419: [Latn, [AM], español de América Latina]
@@ -497,7 +498,7 @@ languages:
   shi: [shi-latn]
   shn: [Mymr, [AS], လိၵ်ႈတႆး]
   si: [Sinh, [AS], සිංහල]
-  simple: [Latn, [WW], Simple English]
+  simple: [en-simple]
   sjd: [Cyrl, [EU], Кӣллт са̄мь кӣлл]
   sje: [Latn, [EU], bidumsámegiella]
   sjo: [Mong, [AS], ᠰᡞᠪᡝ ᡤᡞᠰᡠᠨ]