fixed css selector to work with newer jquery versions

git-svn-id: http://dev.piwik.org/svn/trunk@7076 59fd770c-687e-43c8-a1e3-f5a4ff64c105

plugins/Dashboard/templates/dashboardObject.js

@@ -349,9 +349,9 @@
         var widgetContent = '<div class="sortable" widgetId="'+uniqueId+'"></div>';
 
         if (addWidgetOnTop) {
-            $('.col::nth-child('+columnNumber+')', dashboardElement).prepend(widgetContent);
+            $('.col:nth-child('+columnNumber+')', dashboardElement).prepend(widgetContent);
         } else {
-            $('.col::nth-child('+columnNumber+')', dashboardElement).append(widgetContent);
+            $('.col:nth-child('+columnNumber+')', dashboardElement).append(widgetContent);
         }
 
         $('[widgetId='+uniqueId+']', dashboardElement).dashboardWidget({