[fix] Only use S3 storage when AWS_ACCESS_KEY_ID is present

Author: sman591

config/environments/production.rb

@@ -39,7 +39,7 @@
   # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
 
   # Store uploaded files on the local file system (see config/storage.yml for options)
-  config.active_storage.service = :amazon
+  config.active_storage.service = ENV['AWS_ACCESS_KEY_ID'].present? ? :amazon : :local
 
   # Mount Action Cable outside main process or domain
   # config.action_cable.mount_path = nil