v2/handler: emit protocol errors as handler errors
v2/handler: emit protocol errors as handler errors

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