Fix address-dependent domains for IPv6.

Thanks to Paul Maddock for spotting this.
It seems to have been broken forever.

src/lease.c

@@ -87,7 +87,7 @@ static int read_leases(time_t now, FILE *leasestream)
 	    if ((lease = lease6_allocate(&addr.addr.addr6, lease_type)))
 	      {
 		lease_set_iaid(lease, strtoul(s, NULL, 10));
-		domain = get_domain6((struct in6_addr *)lease->hwaddr);
+		domain = get_domain6(&lease->addr6);
 	      }
 	  }
 #endif