don't show Bad Line warning for empty strings

stats.js

@@ -163,6 +163,9 @@ config.configFile(process.argv[2], function (config, oldConfig) {
       }
 
       for (var midx in metrics) {
+        if (metrics[midx].length == 0) {
+          continue;
+        }
         if (config.dumpMessages) {
           l.log(metrics[midx].toString());
         }