TChannelRequest: refactor #shouldRetry => #maybeAppRetry
TChannelRequest: refactor #shouldRetry => #maybeAppRetry

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