[py] Update TChannel() docstring
[py] Update TChannel() docstring

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