Fix build error on Python 3
Fix build error on Python 3

EaseCloud/wechatpy,zhaoqz/wechatpy,cloverstd/wechatpy,Dufy/wechatpy,chenjiancan/wechatpy,wechatpy/wechatpy,zhaoqz/wechatpy,tdautc19841202/wechatpy,EaseCloud/wechatpy,cloverstd/wechatpy,Luckyseal/wechatpy,mruse/wechatpy,Luckyseal/wechatpy,jxtech/wechatpy,zaihui/wechatpy,zaihui/wechatpy,Dufy/wechatpy,hunter007/wechatpy,navcat/wechatpy,tdautc19841202/wechatpy,mruse/wechatpy,messense/wechatpy,chenjiancan/wechatpy,tdautc19841202/wechatpy,navcat/wechatpy,Luckyseal/wechatpy,hunter007/wechatpy