builder: delete sandbox in a goroutine for performance
builder: delete sandbox in a goroutine for performance

Signed-off-by: Tonis Tiigi <c2470c48b2d3312d61f94f18d3a1cd113d1915ad@gmail.com>
unclejack/docker,kolyshkin/moby,rremer/moby,x1022as/docker,bearstech/moby,dmcgowan/docker,nalind/docker,flavio/docker,jthelin/docker,konstruktoid/docker-upstream,Mokolea/docker,nalind/docker,yongtang/docker,yosifkit/docker,crosbymichael/docker,jthelin/docker,konstruktoid/docker-upstream,unclejack/docker,moul/docker,konstruktoid/docker-upstream,dims/docker,jlhawn/docker,jvanz/docker,moul/docker,yosifkit/docker,mahak/docker,dims/docker,yongtang/docker,konstruktoid/docker-upstream,gnailuy/docker,konstruktoid/docker-1,konstruktoid/docker-1,mahak/docker,thaJeztah/docker,Mokolea/docker,flavio/docker,dmcgowan/docker,djs55/docker,kolyshkin/moby,mikebrow/docker,SvenDowideit/docker,laijs/moby,trebonian/docker,Mokolea/docker,nawawi/docker,trebonian/docker,thaJeztah/docker,rancher/docker,x1022as/docker,jameszhan/docker,justincormack/docker,bearstech/moby,jvanz/docker,jwhonce/docker,mahak/docker,estesp/docker,maxamillion/docker,ibuildthecloud/docker,estesp/docker,paralin/docker,nalind/docker,tmp6154/docker,AkihiroSuda/docker,paralin/docker,kojiromike/docker,kolyshkin/moby,ibuildthecloud/docker,bearstech/moby,jameszhan/docker,thaJeztah/docker,KarthikNayak/docker,yosifkit/docker,mikebrow/docker,pradipd/moby,mikebrow/docker,rremer/moby,docker/docker,Mokolea/docker,paralin/docker,kojiromike/docker,jimjag/docker,nawawi/docker,moul/docker,moul/docker,ibuildthecloud/docker,cpuguy83/docker,nawawi/docker,paralin/docker,docker/docker,maxamillion/docker,jwhonce/docker,pradipd/moby,vdemeester/docker,vdemeester/docker,laijs/moby,jlhawn/docker,jimjag/docker,trebonian/docker,jameszhan/docker,moby/moby,mahak/docker,gnailuy/docker,trebonian/docker,dmcgowan/docker,Ramzec/docker,laijs/docker,yongtang/docker,ibuildthecloud/docker,nalind/docker,maxamillion/docker,jimjag/docker,flavio/docker,flavio/docker,cpuguy83/docker,Ramzec/docker,moby/moby,tmp6154/docker,moby/moby,nawawi/docker,Ramzec/docker,gnailuy/docker,AkihiroSuda/docker,Ramzec/docker,KarthikNayak/docker,AkihiroSuda/docker,dims/docker,rremer/moby,SvenDowideit/docker,x1022as/docker,djs55/docker,estesp/docker,gnailuy/docker,jimjag/docker,cpuguy83/docker,yosifkit/docker,scotttlin/docker,laijs/moby,crosbymichael/docker,docker/docker,jvanz/docker,kojiromike/docker,scotttlin/docker,justincormack/docker,djs55/docker,laijs/docker,AkihiroSuda/docker,vdemeester/docker,unclejack/docker,justincormack/docker,tmp6154/docker,crosbymichael/docker,jwhonce/docker,moby/moby,thaJeztah/docker,rancher/docker,pradipd/moby,laijs/docker,jlhawn/docker,rancher/docker,bearstech/moby,scotttlin/docker,cpuguy83/docker,KarthikNayak/docker,SvenDowideit/docker,konstruktoid/docker-1,ibuildthecloud/docker