Using bigger image to run scale test in BBSim

Change-Id: I0179337b9ee82acc5b0b71a374413e0e078306e6
diff --git a/jjb/bbr.yaml b/jjb/bbr.yaml
index 3324f33..12b9da2 100644
--- a/jjb/bbr.yaml
+++ b/jjb/bbr.yaml
@@ -43,5 +43,5 @@
     parameters:
       - string:
           name: executorNode
-          default: 'ubuntu16.04-basebuild-1c-2g'
+          default: 'ubuntu16.04-basebuild-4c-8g'
           description: 'Name of the Jenkins node to run the job on'