refactor: 移除 MailClient 配置项

#Comment
测试邮件与正式邮件配置项使用同一个

src/client/Bootstrap.Client/Controllers/ToolsController.cs

@@ -1,4 +1,4 @@
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using Bootstrap.Client.Extensions;
 using Bootstrap.Client.Models;
 using Longbow.Data;
@@ -51,7 +51,7 @@ namespace Bootstrap.Client
             }
             else
             {
-                var section = config.GetSection("MailClient");
+                var section = config.GetSection("SmtpClient");
                 var smtpHost = section.GetValue("Host", "smtp.163.com");
                 var password = section.GetValue("Password", "");
                 var from = section.GetValue("From", "");

src/client/Bootstrap.Client/appsettings.json

@@ -56,14 +56,6 @@
     "From": "honeywell_mes@163.com",
     "To": "argo@163.com"
   },
-  "MailClient": {
-    "Host": "smtp.exmail.qq.com",
-    "Port": 587,
-    "EnableSsl": true,
-    "Password": "",
-    "From": "ba-support@dsnixi.com",
-    "To": "argo@163.com"
-  },
   "AllowOrigins": "http://localhost,http://argo.zylweb.cn",
   "LongbowCache": {
     "Enabled": true,