remove empty query default elements

(c) Copyright IBM Corp. 2016

Author: peller

urth-viz-query.html

@@ -191,12 +191,12 @@ <h3 class="query-label">Filters (matches all):</h3>
             // n-element array with shape to fit query form
             filters: {
                 type: Array,
-                value: function() { return [{ col: null, op: null, val: null }]; }
+                value: function() { return []; }
             },
 
             groups: {
                 type: Array,
-                value: function() { return [{ col: null, aggregators: [] }]; }
+                value: function() { return []; }
             }
         },