TChannelConnection: factor out opKey in onTimeoutCheck
TChannelConnection: factor out opKey in onTimeoutCheck

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