1. 调整用户名可以设置为最小一位

(cherry picked from commit 0d31b54f1c13c5851ca448f9d55c4b2d4b345458)

zt-module-system/zt-module-system-server/src/main/java/com/zt/plat/module/system/controller/admin/user/vo/user/UserSaveReqVO.java

@@ -29,7 +29,7 @@ public class UserSaveReqVO {
     @Schema(description = "用户账号", requiredMode = Schema.RequiredMode.REQUIRED, example = "zt")
     @NotBlank(message = "用户账号不能为空")
     @Pattern(regexp = "^[a-zA-Z0-9]+$", message = "用户账号由 数字、字母 组成")
-    @Size(min = 4, max = 30, message = "用户账号长度为 4-30 个字符")
+    @Size(min = 1, max = 30, message = "用户账号长度为 1-30 个字符")
     @DiffLogField(name = "用户账号")
     private String username;