fix unittest: encoding_aes_key不够长
fix unittest: encoding_aes_key不够长

zhaoqz/wechatpy,messense/wechatpy,zaihui/wechatpy,hunter007/wechatpy,cloverstd/wechatpy,jxtech/wechatpy,zhaoqz/wechatpy,cloverstd/wechatpy,zaihui/wechatpy,wechatpy/wechatpy,hunter007/wechatpy