update faq
update faq

Aoyunyun/jpush-docs,raoxudong/jpush-docs,jpush/jpush-docs,jpush/jpush-docs,raoxudong/jpush-docs,jpush/jpush-docs,raoxudong/jpush-docs,Aoyunyun/jpush-docs,Aoyunyun/jpush-docs,raoxudong/jpush-docs,Aoyunyun/jpush-docs,jpush/jpush-docs