Remove duplicate property checkbox ui grid style

Author: mrtuvn

app/design/adminhtml/Magento/backend/Magento_Ui/web/css/source/module/_data-grid.less

@@ -392,7 +392,6 @@ body._in-resize {
         overflow: hidden;
         padding: 0;
         vertical-align: top;
-        vertical-align: middle;
         width: @control-checkbox-radio__size + @data-grid-checkbox-cell-inner__padding-horizontal * 2;
 
         &:hover {