go: clean should not remove _string.go files
go: clean should not remove _string.go files

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