Update global-jjb to v0.31.0

This fixes an issue causing failures in jobs using deploy-maven-files
script.

Change-Id: I56519b2c242bab817a26979bf167044b8d6c2eaf
Signed-off-by: Eric Ball <eball@linuxfoundation.org>

diff --git a/global-jjb b/global-jjb
index 8b56734..4ada8fb 160000 (submodule)
--- a/global-jjb
+++ b/global-jjb
@@ -1 +1 @@
-Subproject commit 8b56734eada742094399d6e52cbc2ddef7b39b2c
+Subproject commit 4ada8fbad994cdcb78c547742f4fe97456949193