Fix 500 on repo archive download

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/controllers/projects/repositories_controller.rb

@@ -22,7 +22,7 @@ class Projects::RepositoriesController < Projects::ApplicationController
     if file_path
       # Send file to user
-      response.headers["Content-Length"] = File.Open(file_path).size.to_s
+      response.headers["Content-Length"] = File.open(file_path).size.to_s
       send_file file_path
     else
       render_404