nit - remove unneeded keychain.service
nit - remove unneeded keychain.service

Summary:
this is a nit to reduce the surface area of the keychain.service
usages

Test Plan: run the tutorial server + client, see the reversed string. amazing!

Reviewed By: andrei.bajenov@fb.com

Subscribers: ruibalp, alandau, mshneer

FB internal diff: D1703655

Signature: t1:1703655:1417567110:6748ec67e4988107ff6e3c605d7c80bba3ebfae9

SergeyMakarenko/fbthrift,soumith/fbthrift,LinusU/fbthrift,sinjar666/fbthrift,HankFaan/fbthrift,LinusU/fbthrift,chjp2046/fbthrift,jesboat/fbthrift,kangkot/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,LinusU/fbthrift,raphaelamorim/fbthrift,fengshao0907/fbthrift,soumith/fbthrift,soumith/fbthrift,LinusU/fbthrift,chjp2046/fbthrift,fengshao0907/fbthrift,project-zerus/fbthrift,chjp2046/fbthrift,uber/fbthrift,facebook/fbthrift,raphaelamorim/fbthrift,getyourguide/fbthrift,getyourguide/fbthrift,uber/fbthrift,HankFaan/fbthrift,LinusU/fbthrift,HankFaan/fbthrift,chjp2046/fbthrift,kangkot/fbthrift,jesboat/fbthrift,sinjar666/fbthrift,SergeyMakarenko/fbthrift,raphaelamorim/fbthrift,SergeyMakarenko/fbthrift,maxwell-demon/fbthrift,raphaelamorim/fbthrift,HankFaan/fbthrift,getyourguide/fbthrift,soumith/fbthrift,raphaelamorim/fbthrift,raphaelamorim/fbthrift,Orvid/fbthrift,chjp2046/fbthrift,sinjar666/fbthrift,raphaelamorim/fbthrift,uber/fbthrift,raphaelamorim/fbthrift,maxwell-demon/fbthrift,sinjar666/fbthrift,Orvid/fbthrift,Orvid/fbthrift,SergeyMakarenko/fbthrift,fengshao0907/fbthrift,chjp2046/fbthrift,soumith/fbthrift,HankFaan/fbthrift,guker/fbthrift,facebook/fbthrift,project-zerus/fbthrift,project-zerus/fbthrift,uber/fbthrift,guker/fbthrift,Orvid/fbthrift,project-zerus/fbthrift,kangkot/fbthrift,guker/fbthrift,facebook/fbthrift,sinjar666/fbthrift,maxwell-demon/fbthrift,fengshao0907/fbthrift,raphaelamorim/fbthrift,kangkot/fbthrift,Orvid/fbthrift,chjp2046/fbthrift,soumith/fbthrift,chjp2046/fbthrift,facebook/fbthrift,getyourguide/fbthrift,jesboat/fbthrift,sinjar666/fbthrift,sinjar666/fbthrift,SergeyMakarenko/fbthrift,jesboat/fbthrift,maxwell-demon/fbthrift,LinusU/fbthrift,facebook/fbthrift,getyourguide/fbthrift,facebook/fbthrift,getyourguide/fbthrift,maxwell-demon/fbthrift,fengshao0907/fbthrift,SergeyMakarenko/fbthrift,HankFaan/fbthrift,Orvid/fbthrift,chjp2046/fbthrift,sinjar666/fbthrift,jesboat/fbthrift,Orvid/fbthrift,maxwell-demon/fbthrift,sinjar666/fbthrift,soumith/fbthrift,jesboat/fbthrift,maxwell-demon/fbthrift,LinusU/fbthrift,uber/fbthrift,guker/fbthrift,soumith/fbthrift,project-zerus/fbthrift,getyourguide/fbthrift,maxwell-demon/fbthrift,SergeyMakarenko/fbthrift,fengshao0907/fbthrift,LinusU/fbthrift,jesboat/fbthrift,uber/fbthrift,HankFaan/fbthrift,fengshao0907/fbthrift,project-zerus/fbthrift,kangkot/fbthrift,guker/fbthrift,kangkot/fbthrift,fengshao0907/fbthrift,maxwell-demon/fbthrift,guker/fbthrift,uber/fbthrift,getyourguide/fbthrift,jesboat/fbthrift,facebook/fbthrift,SergeyMakarenko/fbthrift,HankFaan/fbthrift,fengshao0907/fbthrift,project-zerus/fbthrift,Orvid/fbthrift,fengshao0907/fbthrift,getyourguide/fbthrift,LinusU/fbthrift,HankFaan/fbthrift,Orvid/fbthrift,project-zerus/fbthrift,fengshao0907/fbthrift,guker/fbthrift,guker/fbthrift,kangkot/fbthrift,project-zerus/fbthrift,guker/fbthrift,SergeyMakarenko/fbthrift,jesboat/fbthrift,project-zerus/fbthrift,sinjar666/fbthrift,guker/fbthrift,chjp2046/fbthrift,kangkot/fbthrift,project-zerus/fbthrift,kangkot/fbthrift,sinjar666/fbthrift,raphaelamorim/fbthrift,guker/fbthrift,HankFaan/fbthrift,chjp2046/fbthrift,SergeyMakarenko/fbthrift,uber/fbthrift,uber/fbthrift,facebook/fbthrift,soumith/fbthrift,jesboat/fbthrift,soumith/fbthrift,uber/fbthrift,getyourguide/fbthrift,LinusU/fbthrift,getyourguide/fbthrift,uber/fbthrift,soumith/fbthrift,uber/fbthrift,jesboat/fbthrift,SergeyMakarenko/fbthrift,maxwell-demon/fbthrift,LinusU/fbthrift,HankFaan/fbthrift,jesboat/fbthrift,facebook/fbthrift,raphaelamorim/fbthrift,kangkot/fbthrift,Orvid/fbthrift,kangkot/fbthrift,Orvid/fbthrift,project-zerus/fbthrift,maxwell-demon/fbthrift,chjp2046/fbthrift