Minor bug fix.

tbsetup/snmpit_test/snmpit_test.in

@@ -3216,6 +3216,8 @@ sub doMakeVlan($$@) {
 	#
 	foreach my $port (@ports) {
 	    my $vlan = VLan->FindVlanByPort(undef, $port);
+	    next
+		if (!defined($vlan));
 	    
 	    if (defined($source_vlan) && !$vlan->SameVlan($source_vlan)) {
 		if (IsPortTagged($port)) {