replace placeholders with empty string

plugins/ExampleRssWidget/Widgets.php

@@ -57,7 +57,7 @@ class Widgets extends \Piwik\Plugin\Widgets
     private function error($e)
     {
         return '<div class="pk-emptyDataTable">'
-             . Piwik::translate('General_ErrorRequest')
+             . Piwik::translate('General_ErrorRequest', array('', ''))
              . ' - ' . $e->getMessage() . '</div>';
     }
 }

plugins/MultiSites/angularjs/dashboard/dashboard.html

@@ -58,7 +58,7 @@
             <tr ng-if="model.errorLoadingSites">
                 <td colspan="7">
                     <div class="notification system notification-error">
-                        {{ 'General_ErrorRequest'|translate }}
+                        {{ 'General_ErrorRequest'|translate('', '') }}
                     </div>
                 </td>
             </tr>