Fix panic in hijack
Fix panic in hijack

Signed-off-by: Tibor Vass <3f1326dff4d85ad4ec938fb33f64575ace96db26@docker.com>

SvenDowideit/docker,rhatdan/docker,mahak/docker,djs55/docker,cyphar/docker,yongtang/docker,scotttlin/docker,moul/docker,x1022as/docker,ibuildthecloud/docker,rancher/docker,ibuildthecloud/docker,bearstech/moby,maxamillion/docker,konstruktoid/docker-1,konstruktoid/docker-upstream,mkumatag/docker,mike1729/docker,rhatdan/docker,sterchelen/docker,raja-sami-10p/moby,raja-sami-10p/moby,kojiromike/docker,gnailuy/docker,jameszhan/docker,noironetworks/docker,johnstep/moby-moby,vdemeester/docker,cpuguy83/docker,nawawi/docker,kojiromike/docker,danyalKhaliq10p/moby,mikebrow/docker,amatsus/docker,yosifkit/docker,kolyshkin/docker,cyphar/docker,coolljt0725/docker,gnailuy/docker,scotttlin/docker,laijs/moby,ndeloof/docker,miminar/docker,pramodhkp/moby,nalind/docker,rremer/moby,flavio/docker,dims/docker,bearstech/moby,paralin/docker,unclejack/docker,yongtang/docker,maxamillion/docker,PatrickLang/moby,Mokolea/docker,AkihiroSuda/docker,Ramzec/docker,SvenDowideit/docker,hqhq/moby,tophj-ibm/docker,bearstech/moby,vdemeester/docker,yummypeng/docker,PatrickLang/moby,tmp6154/docker,miminar/docker,paralin/docker,estesp/docker,nawawi/docker,mahak/docker,AkihiroSuda/docker,liaoqingwei/docker,duglin/docker,madhanrm/docker,thaJeztah/docker,crosbymichael/docker,KarthikNayak/docker,coreos/docker,dmcgowan/docker,crosbymichael/docker,tophj-ibm/moby,laijs/docker,docker/docker,madhanrm/docker,hqhq/moby,pradipd/moby,jvanz/docker,KingEmet/docker,laijs/moby,ripcurld0/moby,yongtang/docker,cyphar/docker,dims/docker,kolyshkin/moby,rancher/docker,whuwxl/docker,tmp6154/docker,duglin/docker,Mokolea/docker,estesp/docker,yosifkit/docker,mahak/docker,kolyshkin/moby,pradipd/moby,srust/docker,liaoqingwei/docker,raja-sami-10p/moby,x1022as/docker,docker/docker,nawawi/docker,allencloud/docker,thaJeztah/docker,nalind/docker,dccurtis/docker,AkihiroSuda/docker,johnstep/moby-moby,unclejack/docker,vdemeester/docker,nalind/docker,fcrisciani/docker,ripcurld0/moby,jthelin/docker,YuPengZTE/docker,thaJeztah/docker,srust/docker,mixja/docker,cpuguy83/docker,jameszhan/docker,docker/docker,Mokolea/docker,mkumatag/docker,djs55/docker,moul/docker,mixja/docker,shishir-a412ed/docker,tophj-ibm/docker,unclejack/docker,konstruktoid/docker-upstream,mahak/docker,jameszhan/docker,jvanz/docker,dccurtis/docker,KarthikNayak/docker,naveed-jamil-tenpearls/moby,pramodhkp/moby,trebonian/docker,thaJeztah/docker,shishir-a412ed/docker,allencloud/docker,cpuguy83/docker,mikebrow/docker,dmcgowan/docker,fcrisciani/docker,paralin/docker,tonistiigi/docker,AkihiroSuda/docker,johnstep/moby-moby,pradipd/moby,allencloud/docker,jimjag/docker,srust/docker,nalind/docker,justincormack/docker,trebonian/docker,trebonian/docker,tmp6154/docker,YuPengZTE/docker,cpuguy83/docker,yummypeng/docker,duglin/docker,gnailuy/docker,madhanrm/docker,haveatry/docker,konstruktoid/docker-1,moby/moby,dsheets/moby,PatrickLang/moby,noironetworks/docker,shishir-a412ed/docker,flavio/docker,rremer/moby,dims/docker,konstruktoid/docker-upstream,jthelin/docker,trebonian/docker,mikebrow/docker,yosifkit/docker,Ramzec/docker,Ramzec/docker,tonistiigi/docker,moby/moby,jwhonce/docker,mkumatag/docker,haveatry/docker,liaoqingwei/docker,justincormack/docker,KingEmet/docker,coreos/docker,laijs/docker,bearstech/moby,crosbymichael/docker,amatsus/docker,ndeloof/docker,jimjag/docker,scotttlin/docker,moby/moby,jlhawn/docker,moby/moby,sterchelen/docker,mike1729/docker,dsheets/moby,konstruktoid/docker-upstream,maxamillion/docker,tophj-ibm/moby,fcrisciani/docker,flavio/docker,nawawi/docker,jimjag/docker,yosifkit/docker,jvanz/docker,jwhonce/docker,dccurtis/docker,Ramzec/docker,naveed-jamil-tenpearls/moby,whuwxl/docker,Mokolea/docker,naveed-jamil-tenpearls/moby,kojiromike/docker,pramodhkp/moby,coolljt0725/docker,tklauser/docker,moul/docker,dmcgowan/docker,SvenDowideit/docker,tonistiigi/docker,paralin/docker,flavio/docker,haveatry/docker,jlhawn/docker,laijs/docker,justincormack/docker,jlhawn/docker,laijs/moby,ndeloof/docker,estesp/docker,rancher/docker,hqhq/moby,KarthikNayak/docker,x1022as/docker,tklauser/docker,danyalKhaliq10p/moby,jwhonce/docker,miminar/docker,whuwxl/docker,moul/docker,coreos/docker,jimjag/docker,yummypeng/docker,YuPengZTE/docker,kolyshkin/docker,mixja/docker,KingEmet/docker,ibuildthecloud/docker,tophj-ibm/docker,mike1729/docker,danyalKhaliq10p/moby,djs55/docker,dsheets/moby,kolyshkin/moby,rremer/moby,ibuildthecloud/docker,ibuildthecloud/docker,ripcurld0/moby,coolljt0725/docker,amatsus/docker,tophj-ibm/moby,sterchelen/docker,rhatdan/docker,tklauser/docker,gnailuy/docker,konstruktoid/docker-1,noironetworks/docker