xtables: fix missing afinfo configuration

I noticed that the iprange match in IPv6 was broken, fix it
by overriding the default family (IPv4) if -6 is passed.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/iptables/xtables-restore.c b/iptables/xtables-restore.c
index a5d2a65..e66f10c 100644
--- a/iptables/xtables-restore.c
+++ b/iptables/xtables-restore.c
@@ -233,6 +233,7 @@
 				break;
 			case '6':
 				h.family = AF_INET6;
+				xtables_set_nfproto(AF_INET6);
 				break;
 		}
 	}
diff --git a/iptables/xtables-save.c b/iptables/xtables-save.c
index 49b859d..41ceaf5 100644
--- a/iptables/xtables-save.c
+++ b/iptables/xtables-save.c
@@ -125,6 +125,7 @@
 			break;
 		case '6':
 			h.family = AF_INET6;
+			xtables_set_nfproto(AF_INET6);
 			break;
 		}
 	}
diff --git a/iptables/xtables.c b/iptables/xtables.c
index c058567..4e8d362 100644
--- a/iptables/xtables.c
+++ b/iptables/xtables.c
@@ -1045,6 +1045,7 @@
 
 		case '6':
 			args.family = AF_INET6;
+			xtables_set_nfproto(AF_INET6);
 			break;
 
 		case 1: /* non option */