[IMP] web: pivot don't repeat total header 2 times

opw-687243

addons/web/static/src/js/views/pivot_view.js

@@ -679,7 +679,6 @@ var PivotView = View.extend({
         if (width > 1) {
             var total_cell = {width:nbr_measures, height: depth, title:""};
             if (nbr_measures === 1) {
-                total_cell.title = this.measures[this.active_measures[0]].string;
                 total_cell.total = true;
             }
             result[0].push(total_cell);