jenkins: update poky version 2.3.2

The sysmobts 2017 releases are using poky 2.3.2

Change-Id: If6e8a5702e4c9b24e758e3aa5f390e786c51c384
diff --git a/contrib/jenkins-build-osmo-bts-sysmo.sh b/contrib/jenkins-build-osmo-bts-sysmo.sh
index 1a8876d..98f8249 100755
--- a/contrib/jenkins-build-osmo-bts-sysmo.sh
+++ b/contrib/jenkins-build-osmo-bts-sysmo.sh
@@ -4,7 +4,7 @@
 _poky_version="$POKY_VERSION"
 _poky_path="$POKY_PATH"
 
-[ -z "$_poky_version" ] && _poky_version="1.5.4"
+[ -z "$_poky_version" ] && _poky_version="2.3.2"
 [ -z "$_poky_path" ] && _poky_path="/opt/poky/$_poky_version"
 
 . "$_poky_path/environment-setup-armv5te-poky-linux-gnueabi"