Add check for IP_NF_FILTER

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>

contrib/check-config.sh

@@ -135,7 +135,7 @@ flags=(
 	DEVPTS_MULTIPLE_INSTANCES
 	CGROUPS CGROUP_CPUACCT CGROUP_DEVICE CGROUP_FREEZER CGROUP_SCHED
 	MACVLAN VETH BRIDGE
-	NF_NAT_IPV4 IP_NF_TARGET_MASQUERADE
+	NF_NAT_IPV4 IP_NF_FILTER IP_NF_TARGET_MASQUERADE
 	NETFILTER_XT_MATCH_{ADDRTYPE,CONNTRACK}
 	NF_NAT NF_NAT_NEEDED
 )