fix: remove fake Content-Length header for non-2xx image responses (#6062)

* fix: remove Content-Length header for non-2xx image responses

it's a lie

* fix: remove check

---------

Co-authored-by: Fijxu <fijxu@nadeko.net>

src/invidious/routes/images.cr

@@ -154,10 +154,6 @@ module Invidious::Routes::Images
 
     env.response.headers["Access-Control-Allow-Origin"] = "*"
 
-    if response.status_code >= 300
-      return env.response.headers.delete("Transfer-Encoding")
-    end
-
     return Helpers.proxy_file(response, env)
   end
 end