Fixing issue with auto checkboxes in data-table

src/data-table/data-table.js

@@ -123,7 +123,6 @@ MaterialDataTable.prototype.init = function() {
       var headerCheckbox = this.createCheckbox_(null, rows);
       th.appendChild(headerCheckbox);
       firstHeader.parentElement.insertBefore(th, firstHeader);
-    }
 
       for (var i = 0; i < rows.length; i++) {
         var firstCell = rows[i].querySelector('td');
@@ -134,6 +133,7 @@ MaterialDataTable.prototype.init = function() {
           rows[i].insertBefore(td, firstCell);
         }
       }
+    }
 
     this.element_.classList.add(this.CssClasses_.IS_UPGRADED);
   }