【优化】优化分享策略，防止出现两个用户互为各自上级的问题。

CoreCms.Net.Services/User/CoreCmsUserServices.cs

@@ -373,6 +373,12 @@ public class CoreCmsUserServices : BaseServices<CoreCmsUser>, ICoreCmsUserServic
             return jm;
         }
 
+        if (superior.parentId == user.id)
+        {
+            jm.msg = "不允许双方互相设置为上级";
+            return jm;
+        }
+
         var flag = IsInvited(userId, superiorId);
         if (flag)
         {

CoreCms.Net.Web.Admin/Controllers/User/CoreCmsUserController.cs

@@ -1118,6 +1118,13 @@ namespace CoreCms.Net.Web.Admin.Controllers
                     jm.msg = "不存在此上级信息";
                     return jm;
                 }
+
+
+                if (parentObj.parentId == model.id)
+                {
+                    jm.msg = "不允许双方互相设置为上级";
+                    return jm;
+                }
             }
             else
             {