* zserv.c: (zsend_route_multipath) Set the nexthop_num
field correctly. Add NEXTHOP_TYPE_IPV6_IFNAME for v6.
Conditionally set ZAPI_MESSAGE_METRIC flag - only for adds.
(zsend_ipv4_add) cruft, deleted.
(zsend_ipv4_delete) ditto.
(zsend_ipv6_add) ditto.
(zsend_ipv6_delete) ditto.