Fix KeyError if builtins isn't touched.
Fix KeyError if builtins isn't touched.

urbaniak/gunicorn,wong2/gunicorn,mvaled/gunicorn,urbaniak/gunicorn,elelianghh/gunicorn,ccl0326/gunicorn,gtrdotmcs/gunicorn,jamesblunt/gunicorn,GitHublong/gunicorn,jamesblunt/gunicorn,alex/gunicorn,malept/gunicorn,gtrdotmcs/gunicorn,zhoucen/gunicorn,tempbottle/gunicorn,zhoucen/gunicorn,z-fork/gunicorn,tejasmanohar/gunicorn,prezi/gunicorn,malept/gunicorn,harrisonfeng/gunicorn,ccl0326/gunicorn,prezi/gunicorn,wong2/gunicorn,1stvamp/gunicorn,mvaled/gunicorn,gtrdotmcs/gunicorn,mvaled/gunicorn,ammaraskar/gunicorn,alex/gunicorn,alex/gunicorn,prezi/gunicorn,urbaniak/gunicorn,keakon/gunicorn,beni55/gunicorn,zhoucen/gunicorn,jamesblunt/gunicorn,ccl0326/gunicorn,malept/gunicorn,1stvamp/gunicorn,WSDC-NITWarangal/gunicorn,pschanely/gunicorn,pschanely/gunicorn,MrKiven/gunicorn,pschanely/gunicorn,ephes/gunicorn,1stvamp/gunicorn,wong2/gunicorn