Enable SIDEKIQ_REQUEST_STORE by default

config/initializers/sidekiq.rb

@@ -7,7 +7,7 @@ Sidekiq.configure_server do |config|
   config.server_middleware do |chain|
     chain.add Gitlab::SidekiqMiddleware::ArgumentsLogger if ENV['SIDEKIQ_LOG_ARGUMENTS']
     chain.add Gitlab::SidekiqMiddleware::MemoryKiller if ENV['SIDEKIQ_MEMORY_KILLER_MAX_RSS']
-    chain.add Gitlab::SidekiqMiddleware::RequestStoreMiddleware if ENV['SIDEKIQ_REQUEST_STORE']
+    chain.add Gitlab::SidekiqMiddleware::RequestStoreMiddleware unless ENV['SIDEKIQ_REQUEST_STORE'] == '0'
   end
 
   # Sidekiq-cron: load recurring jobs from gitlab.yml