setfb not work with ipv6

[Vladislav V. Prodan]

Sorry...
Instead, "add" to read "change"...

> # setfib 2 route -n add -inet6 default 2001:470:27:140::1
> route: writing to routing socket: File exists
> add net default: gateway 2001:470:27:140::1: route already in table


# setfib 2 route -n change -inet6 default 2001:470:27:140::1
route: writing to routing socket: Address family not supported by 
protocol family
change net default: gateway 2001:470:27:140::1: Address family not 
supported by protocol family