Minor fix for new dashbboard column errors
diff --git a/ambari-metrics-grafana/ambari-metrics/query_ctrl.js b/ambari-metrics-grafana/ambari-metrics/query_ctrl.js
index 5b5c4a9..77f420d 100644
--- a/ambari-metrics-grafana/ambari-metrics/query_ctrl.js
+++ b/ambari-metrics-grafana/ambari-metrics/query_ctrl.js
@@ -131,7 +131,7 @@
                 this.target.seriesAggregator = "none";
             }
         };
-        _this.$watch('target.app', function (newValue) {
+        $scope.$watch('target.app', function (newValue) {
             if (newValue === '') {
                 this.target.metric = '';
                 this.target.hosts = '';