Added sanity test

Author: nigelhorne

lib/VWF/Display/meta_data.pm

@@ -265,6 +265,7 @@ sub get_slow_endpoints_24h {
 	foreach my $row (@rows) {
 		next unless defined $row->{time};
 		next unless defined $row->{duration_ms};
+		next if($row->{duration_ms} <= 0);
 
 		my $tp;
 		eval { $tp = Time::Piece->strptime($row->{time}, '%Y-%m-%d %H:%M:%S') };