added Translation for Filtering On

application/views/timeline/details.php

@@ -1,4 +1,4 @@
 <div class="container">
-    <h5>Filtering on <?php echo $filter ?></h5>
+    <h5><?php echo lang('general_word_filtering_on'); ?> <?php echo $filter ?></h5>
 
     <?php $this->load->view('view_log/partial/log_ajax') ?>