[connman] Set ip6t_ip6 flags if IPv6 rule protocol is set. JB#44205
Flags is required to be set as IP6T_F_PROTO if protocol for IPv6 rule is
being set (
INCLUDEDIR/linux/netfilter_ipv6/ip6_tables.h). Without this
being set, ICMPv6 rules, for example, are installed to ip6tables but no
packet matches the rule as protocol check is skipped in kernel.
Commit in upstream: https://lists.01.org/pipermail/connman/2019-January/023145.html