[IMPROVE] Prevent "App user" from being deleted by the admin (#16373)

packages/rocketchat-i18n/i18n/en.i18n.json

@@ -1276,6 +1276,7 @@
   "error-archived-duplicate-name": "There's an archived channel with name '__room_name__'",
   "error-avatar-invalid-url": "Invalid avatar URL: __url__",
   "error-avatar-url-handling": "Error while handling avatar setting from a URL (__url__) for __username__",
+  "error-cannot-delete-app-user": "Deleting app user is not allowed, uninstall the corresponding app to remove it.",
   "error-cant-invite-for-direct-room": "Can't invite user to direct rooms",
   "error-channels-setdefault-is-same": "The channel default setting is the same as what it would be changed to.",
   "error-channels-setdefault-missing-default-param": "The bodyParam 'default' is required",

packages/rocketchat-i18n/i18n/zh.i18n.json

@@ -1232,6 +1232,7 @@
   "error-archived-duplicate-name": "有一个名为 '__room_name__' 的已归档频道",
   "error-avatar-invalid-url": "无效的头像地址：__url__",
   "error-avatar-url-handling": "为用户 __username__ 从网址 (__url__) 处理头像时出错",
+  "error-cannot-delete-app-user": "不允许直接删除App用户”，请卸载相应的App以移除此用户。",
   "error-cant-invite-for-direct-room": "不能邀请用户进入私聊房间",
   "error-channels-setdefault-is-same": "频道的默认设置与更改的频道相同。",
   "error-channels-setdefault-missing-default-param": "bodyParam 'default' 是必需的",

server/methods/deleteUser.js

@@ -28,6 +28,12 @@ Meteor.methods({
 			});
 		}
 
+		if (user.type === 'app') {
+			throw new Meteor.Error('error-cannot-delete-app-user', 'Deleting app user is not allowed', {
+				method: 'deleteUser',
+			});
+		}
+
 		const adminCount = Meteor.users.find({ roles: 'admin' }).count();
 
 		const userIsAdmin = user.roles.indexOf('admin') > -1;