【修改】公益性岗位实体修改；

Learun.Framework.Ultimate V7/Learun.Framework.Module/Learun.Application.Module/Learun.Application.TwoDevelopment/EducationalAdministration/WelfarePosition/WelfarePositionEntity.cs

@@ -217,7 +217,7 @@ namespace Learun.Application.TwoDevelopment.EducationalAdministration
         /// </summary>
         /// <returns></returns>
         [Column("ISSUEYEAR")]
-        public DateTime? IssueYear { get; set; }
+        public string IssueYear { get; set; }
         /// <summary>
         /// CreateUser
         /// </summary>