v2/handler: classify errors in #handleCallRequest
v2/handler: classify errors in #handleCallRequest

i/tchannel,bunnyblue/tchannel,i/tchannel,hustxiaoc/tchannel,savaki/tchannel,RyanTech/tchannel,chenwenbin928/tchannel,RyanTech/tchannel,Zirpon/tchannel,benfleis/tchannel,hustxiaoc/tchannel,Zirpon/tchannel,sasa233/tchannel,sasa233/tchannel,savaki/tchannel,savaki/tchannel,benfleis/tchannel,vanloswang/tchannel,chenwenbin928/tchannel,bunnyblue/tchannel,sasa233/tchannel,vanloswang/tchannel,vanloswang/tchannel,hustxiaoc/tchannel,Zirpon/tchannel,i/tchannel,benfleis/tchannel,bunnyblue/tchannel,RyanTech/tchannel,chenwenbin928/tchannel