Merge pull request #720 from insomnux/i18n

added gettext in a few strings in backup.php and Discussion.php

admin/backup.php

@@ -32,8 +32,8 @@ $backupFiles = Typecho_Widget::widget('Widget_Backup')->listFiles();
             <div id="backup-secondary" class="col-mb-12 col-tb-4" role="form">
                 <h3><?php _e('恢复数据'); ?></h3>
                 <ul class="typecho-option-tabs clearfix">
-                    <li class="active w-50"><a href="#from-upload">上传</a></li>
-                    <li class="w-50"><a href="#from-server">从服务器</a></li>
+                    <li class="active w-50"><a href="#from-upload"><?php _e('上传'); ?></a></li>
+                    <li class="w-50"><a href="#from-server"><?php _e('从服务器'); ?></a></li>
                 </ul>
 
                 <form action="<?php echo $actionUrl; ?>" id="from-upload" class="tab-content" method="post" enctype="multipart/form-data">