Fixed deleting item with id 0 (#2530)

lib/DataSet.js

@@ -679,7 +679,7 @@ DataSet.prototype.remove = function (id, senderId) {
     item = this._remove(ids[i]);
     if (item) {
       itemId = item[this._fieldId];
-      if (itemId) {
+      if (itemId != undefined) {
         removedIds.push(itemId);
         removedItems.push(item);
       }