Merge pull request 'feat; fixing the default public bug' (#22) from DEV-default-private into develop

Reviewed-by: yuyuanshifu <747342561@qq.com>

routers/repo/attachment.go

@@ -261,6 +261,7 @@ func AddAttachment(ctx *context.Context) {
 	_, err = models.InsertAttachment(&models.Attachment{
 		UUID:       uuid,
 		UploaderID: ctx.User.ID,
+		IsPrivate:  true,
 		Name:       ctx.Query("file_name"),
 		Size:       ctx.QueryInt64("size"),
 		DatasetID:  ctx.QueryInt64("dataset_id"),