fix typo - "english" is not a valid language code (#114166) (#114216)

This example request will succeed, but follow-up requests to run a sync on a connector with this language value will fail.

docs/reference/connector/apis/create-connector-api.asciidoc

@@ -116,7 +116,7 @@ PUT _connector/my-connector
   "name": "My Connector",
   "description": "My Connector to sync data to Elastic index from Google Drive",
   "service_type": "google_drive",
-  "language": "english"
+  "language": "en"
 }
 ----