Remove redundant merge step
Remove redundant merge step

Summary:
We already merge the master_cx into every context in a cycle. This code was a
remnant from an earlier time when the master_cx was merged after. It's just
redundant now.

Reviewed By: avikchaudhuri

Differential Revision: D5696775

fbshipit-source-id: e76d61fb28e501bfd036ea0d47537ac3f108aee5

gabelevi/flow,gabelevi/flow,popham/flow,jamesgpearce/flow,nmote/flow,mroch/flow,ylu1317/flow,samwgoldman/flow,samwgoldman/flow,gabelevi/flow,ylu1317/flow,popham/flow,JonathanUsername/flow,facebook/flow,nmote/flow,JonathanUsername/flow,MichaelDeBoey/flow,jamesgpearce/flow,MichaelDeBoey/flow,claudiopro/flow,facebook/flow,facebook/flow,JonathanUsername/flow,facebook/flow,claudiopro/flow,JonathanUsername/flow,AgentME/flow,TiddoLangerak/flow,nmote/flow,MichaelDeBoey/flow,samwgoldman/flow,ylu1317/flow,gabelevi/flow,TiddoLangerak/flow,nmote/flow,mroch/flow,JonathanUsername/flow,popham/flow,AgentME/flow,JonathanUsername/flow,JonathanUsername/flow,jamesgpearce/flow,MichaelDeBoey/flow,mroch/flow,popham/flow,mroch/flow,nmote/flow,AgentME/flow,nmote/flow,jamesgpearce/flow,AgentME/flow,gabelevi/flow,ylu1317/flow,claudiopro/flow,ylu1317/flow,claudiopro/flow,gabelevi/flow,jamesgpearce/flow,AgentME/flow,jamesgpearce/flow,MichaelDeBoey/flow,nmote/flow,facebook/flow,mroch/flow,mroch/flow,popham/flow,samwgoldman/flow,samwgoldman/flow,samwgoldman/flow,facebook/flow,popham/flow,samwgoldman/flow,claudiopro/flow,jamesgpearce/flow,mroch/flow,gabelevi/flow,TiddoLangerak/flow,popham/flow,TiddoLangerak/flow,facebook/flow,TiddoLangerak/flow