Fix get_default_host_ip ipv6 address parsing

This is another occurrence of the issue fixed in bug
1786259 with change I30bf655f which occurs when there
are multiple IPv6 gateways present.

Before this change:
$ source openrc
+++++functions-common:get_default_host_ip:776  ip -f inet6 addr show 100
Device "100" does not exist.

This is because the ip route command returns:
default proto ra metric 100 expires 1497sec pref medium
	nexthop via fe80::4e16:fc01:298c:98ed dev ens3 weight 1
	nexthop via fe80::4e16:fc01:2983:88aa dev ens3 weight 1

Related-Bug: #1786259
Change-Id: I7729730df66a4dc7ee11df1d23b19b9c0794b575
1 file changed