更新通用券default_detail报错

https://developers.weixin.qq.com/doc/offiaccount/Cards_and_Offer/Managing_Coupons_Vouchers_and_Cards.html

使用更新卡券的接口时发现更新default_detail会报错, body如下：

{"card_id":"p7DUL6Ll3_FccVpqMKsXnDkz400E","general_coupon":{"default_detail":"dcy xxx"}}

异常信息：

{"errcode":47001,"errmsg":"data format error hint: [kXsBEa0211r254] Error before \":\"dcy xxx\"}}"}