Build thrift generator with python2
Build thrift generator with python2

Summary:
Build fails when built with python3, so always build with 2,
even if the default python installed is 3.

Original patch at https://github.com/facebook/fbthrift/pull/84

Test Plan: watch jenkins

Reviewed By: haijunz@fb.com

Subscribers: alandau, bmatheny, mshneer, yfeldblum

FB internal diff: D1952835

Tasks: 6631976

Signature: t1:1952835:1427742063:3bc71391972d926f2cb5672c0ce2e59f61360d8d

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