Pre Merge pull request !848 from pany_2017/dev

ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/domain/bo/SysUserBo.java

@@ -39,7 +39,7 @@ public class SysUserBo extends BaseEntity {
      */
     @Xss(message = "用户账号不能包含脚本字符")
     @NotBlank(message = "用户账号不能为空")
-    @Size(min = 0, max = 30, message = "用户账号长度不能超过{max}个字符")
+    @Size(min = 2, max = 30, message = "用户账号长度必须在{min}到{max}个字符之间")
     private String userName;
 
     /**