fixed IE-specific bug which could allow it to try to call the overrideCallback when it doesn't exist
fixed IE-specific bug which could allow it to try to call the overrideCallback when it doesn't exist

vtex/curl,marian-r/curl,djkost85/curl-1,jaredcacurak/curl,jaredcacurak/curl,marian-r/curl,djkost85/curl-1,vtex/curl,runt18/curl,jaredcacurak/curl,marian-r/curl,dfd07d/curl,runt18/curl,runt18/curl,cujojs/curl,vtex/curl,cujojs/curl,dfd07d/curl,cujojs/curl,dfd07d/curl,djkost85/curl-1