update Admin.NET/Admin.NET.Core/Entity/SysConfig.cs.

系统参数配置表Code属性增加IsUnique=true，种子数据无法校验唯一，确保入库的配置编码唯一

Signed-off-by: Lzh666 <422235757@qq.com>

Admin.NET/Admin.NET.Core/Entity/SysConfig.cs

@@ -12,7 +12,7 @@ namespace Admin.NET.Core;
 [SugarTable(null, "系统参数配置表")]
 [SysTable]
 [SugarIndex("index_{table}_N", nameof(Name), OrderByType.Asc)]
-[SugarIndex("index_{table}_C", nameof(Code), OrderByType.Asc)]
+[SugarIndex("index_{table}_C", nameof(Code), OrderByType.Asc, IsUnique = true)]
 public partial class SysConfig : EntityBase
 {
     /// <summary>