doc/requirements: correct statement about AIO
doc/requirements: correct statement about AIO

Signed-off-by: Cole Miller <6b0d31c0d563223024da45691584643ac78c96e8@cole-miller.net>

lxc/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,stgraber/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd