MAGETWO-83282: Backport 2.1-develop] Fix datetime type product that show current date when is empty in grids #12033

 - Merge Pull Request #12033 from enriquei4/magento2:DONT-SHOW-UNSETDATE
 - Merged commits:
   1. 9598f4a
   2. 8933489

Author: omiroshnichenko

app/code/Magento/Ui/view/base/web/js/grid/columns/date.js

@@ -35,7 +35,7 @@ define([
         getLabel: function (value, format) {
             var date = moment(this._super());
 
-            date = date.isValid() ?
+            date = date.isValid() && value[this.index] ?
                 date.format(format || this.dateFormat) :
                 '';