邮件详情，修正uid为0的情况

@@ -1067,7 +1067,7 @@ class Home extends Base {
             }
 
             // 循环几次
-            if($data['uid']&&$sync_num < 1){
+            if($data['uid'] >= 0 && $sync_num < 1){
                 $folder = db()->value(folderSql::first(['id'=>$data['folder_id']],'origin_folder'));
                 try{
                     (new SyncMail($data['email_id']))->mail($folder,[$data['uid']],true);