fix InhibitIPv4 nil panic
fix InhibitIPv4 nil panic

Signed-off-by: Wang Yumu <c2e6835454d72e3aeb0db2770517bcb02daf1564@qq.com>

moul/docker,nawawi/docker,flavio/docker,vdemeester/docker,moby/moby,trebonian/docker,nalind/docker,paralin/docker,Mokolea/docker,cpuguy83/docker,gnailuy/docker,paralin/docker,Ramzec/docker,trebonian/docker,AkihiroSuda/docker,jameszhan/docker,thaJeztah/docker,bearstech/moby,bearstech/moby,yosifkit/docker,nalind/docker,moul/docker,gnailuy/docker,moby/moby,flavio/docker,jameszhan/docker,mahak/docker,flavio/docker,jthelin/docker,moul/docker,AkihiroSuda/docker,bearstech/moby,vdemeester/docker,yosifkit/docker,konstruktoid/docker-upstream,nawawi/docker,cpuguy83/docker,moby/moby,thaJeztah/docker,Ramzec/docker,djs55/docker,docker/docker,jimjag/docker,yosifkit/docker,jimjag/docker,paralin/docker,gnailuy/docker,trebonian/docker,bearstech/moby,paralin/docker,moby/moby,thaJeztah/docker,Mokolea/docker,Mokolea/docker,konstruktoid/docker-upstream,konstruktoid/docker-upstream,jimjag/docker,docker/docker,nawawi/docker,mahak/docker,jameszhan/docker,AkihiroSuda/docker,AkihiroSuda/docker,Ramzec/docker,cpuguy83/docker,jimjag/docker,thaJeztah/docker,gnailuy/docker,nawawi/docker,nalind/docker,cpuguy83/docker,konstruktoid/docker-upstream,mahak/docker,trebonian/docker,docker/docker,Mokolea/docker,moul/docker,djs55/docker,yosifkit/docker,djs55/docker,vdemeester/docker,flavio/docker,nalind/docker,mahak/docker,jthelin/docker,Ramzec/docker