we don't need oobgc in ruby 2.2, disable for now

config/initializers/99-unicorn.rb

@@ -5,7 +5,7 @@ if defined? Unicorn::HttpServer
     s.extend(Scheduler::Defer::Unicorn)
   end
 
-  if ENV['UNICORN_ENABLE_OOBGC'] == '1'
+  if ENV['UNICORN_ENABLE_OOBGC'] == '1' && RUBY_VERSION < "2.2.0"
     require 'middleware/unicorn_oobgc'
     Middleware::UnicornOobgc.init
   end