convert-modeswitch.pl: fix message indices

Avoid treating index 0 the same way as not defined.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 1 insertions, 1 deletions

diff --git a/convert-modeswitch.pl b/convert-modeswitch.pl
index 7b2323b..6930e5f 100755
--- a/convert-modeswitch.pl
+++ b/convert-modeswitch.pl
@@ -9,7 +9,7 @@ sub add_message {
 	my $msg = shift;
 	my $val = $messages{$msg};
 
-	$val or do {
+	defined($val) or do {
 		$val = $msg_ctr++;
 		$messages{$msg} = $val;
 	};