Do not create string object for thrift_auth every time we parse response
Do not create string object for thrift_auth every time we parse response

Summary:
simple optimization to avoid creating std::string when looking up an
entry in the map

Test Plan: sandcastle

Reviewed By: yfeldblum@fb.com

Subscribers: alandau, bmatheny, yfeldblum

FB internal diff: D2145049

Signature: t1:2145049:1434069000:484c783dd157e5455c8ce51bdf7dfa67a418e6bf

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