ipops: mask subnet address for ipv6 comparison

- coherent with ipv4 behaviour

(cherry picked from commit a5dd60c8d7e04731f12108838a3c82149e04ef9c)

src/modules/ipops/ipops_mod.c

@@ -415,6 +415,7 @@ int _ip_is_in_subnet_v6(struct in6_addr *ip, char *net, size_t netlen,
 		else ipv6_mask[i] = 0x00;
 	}
 	for (i=0; i<16; i++)  ip->s6_addr[i] &= ipv6_mask[i];
+	for (i=0; i<16; i++)  net_addr.s6_addr[i] &= ipv6_mask[i];
 	if (memcmp(ip->s6_addr, net_addr.s6_addr, sizeof(net_addr.s6_addr)) == 0)
 		return 1;
 	return 0;