symbols don't have #empty? on 1.8.7
symbols don't have #empty? on 1.8.7

fixes #2392

mpapis/bundler,cdwort/bundler,gregkare/bundler,ngpestelos/bundler,christer155/bundler,neslom/bundler,Elffers/bundler,agis-/bundler,seanlinsley/bundler,elovelan/bundler,schaary/bundler,neslom/bundler,mattbrictson/bundler-1,carpodaster/bundler,suhastech/bundler,frsyuki/bundler,asymmetric/bundler,h4ck3rm1k3/bundler,smlance/bundler,Wirachmat/bundler,joshsoftware/bundler,chef/bundler,PG-kura/bundler,PG-kura/bundler,wenderjean/bundler,cstrahan/bundler,davydovanton/bundler,ngpestelos/bundler,jaym/bundler,asutoshpalai/bundler,bronzdoc/bundler,patvice/bundler,Eric-Guo/bundler,jingweno/bundler,smlance/bundler,twcctz500000/bundler,chef/bundler,simplybusiness/bundler,elovelan/bundler,byroot/bundler,seanlinsley/bundler,pjump/bundler,roseweixel/bundler,tgxworld/bundler,tgxworld/bundler,jaym/bundler,anil826/bundler,mdorrance/bundler,sideci-sample/sideci-sample-bundler,bundler/bundler,philnash/bundler,patvice/bundler,danimashu/bundler,asymmetric/bundler,rkh/bundler,e2/bundler,suhastech/bundler,philnash/bundler,ipmobiletech/bundler,pivotal-cf-experimental/bundler,ipmobiletech/bundler,dilumnavanjana/bundler,JuanitoFatas/bundler,jingweno/bundler,TimMoore/bundler,byroot/bundler,steved/bundler,haocafes/bundler,lmtim/bundler,mattbrictson/bundler-1,bronzdoc/bundler,dilumnavanjana/bundler,Eric-Guo/bundler,steved/bundler,mdorrance/bundler,EasonYi/bundler,davydovanton/bundler,robinboening/bundler,Wirachmat/bundler,EthanK28/bundler,haonature888/bundler,ximus/bundler,chulkilee/bundler,vemmaverve/bundler,zhangkuaiji/bundler,CorainChicago/bundler,pjump/bundler,robinboening/bundler,haonaturel/bundler,wenderjean/bundler,RochesterinNYC/bundler,TimMoore/bundler,ximus/bundler,joshsoftware/bundler,chulkilee/bundler,eagletmt/bundler,carpodaster/bundler,lmtim/bundler,jasonkarns/bundler,pivotal-cf-experimental/bundler,gregkare/bundler,masarakki/bundler,kohgpat/bundler,AiyionPrime/bundler,mvz/bundler,masarakki/bundler,anil826/bundler,danimashu/bundler,sideci-sample/sideci-sample-bundler,bundler/bundler,1337807/bundler,EasonYi/bundler,nju520/bundler,haonature/bundler,cdwort/bundler,Teino1978-Corp/Teino1978-Corp-bundler,nju520/bundler,Teino1978-Corp/Teino1978-Corp-bundler,kohgpat/bundler,mvz/bundler,AiyionPrime/bundler,roseweixel/bundler,asutoshpalai/bundler,simplybusiness/bundler,CorainChicago/bundler,zhangkuaiji/bundler,schaary/bundler,RochesterinNYC/bundler,h4ck3rm1k3/bundler,Elffers/bundler,mpapis/bundler,agis-/bundler,frsyuki/bundler,ligi/bundler,christer155/bundler,EthanK28/bundler,cstrahan/bundler,ligi/bundler,jasonkarns/bundler