pre register email+username

resources/lang/zh_CN/label.php

@@ -102,6 +102,8 @@ return [
             'cookie_valid_days' => 'Cookie 有效天数',
             'maximum_upload_speed' => '最大上传速度',
             'maximum_upload_speed_help' => '单种上传速度超过此值账号即刻禁用，单位 Mbps。如：100 Mbps = 12.5 MB/s',
+            'is_invite_pre_email_and_username' => '邀请是否预定邮箱和用户名',
+            'is_invite_pre_email_and_username_help' => "默认: 'No'。若预定，用户注册时不可修改邮箱和用户名",
         ],
     ],
     'user' => [