Fixed missing v6 enable flag in macvlan doc
Fixed missing v6 enable flag in macvlan doc

Signed-off-by: Brent Salisbury <0d72ff0905e7f8b2b879fe7744d4952a9b6d56a3@docker.com>

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