Merge ~adam-collard/maas-ci:maas-ui-sync-just-maas-ui into maas-ci:maas-ui-sync

[Adam Collard]

Just update the UI submodule

[Alberto Donato (ack)]

LGTM

review: Approve

diff --git a/Jenkinsfile b/Jenkinsfile
index b1c2eab..0087720 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -40,8 +40,7 @@ pipeline {
               # branch is more than 10 revisions behind the destination, the
               # merge will fail, and the branch will need to be rebased manually.
               git clone --depth 10 --single-branch --branch ${LP_BRANCH_DEST} git+ssh://[e-mail]/${LP_REPO_DEST} maas
-              git -C maas submodule init
-              git -C maas submodule update --remote
+              git -C maas submodule update --init --remote src/maasui/src
               git -C "$UI_REPO" checkout "${MAAS_UI_REF}"
               '''
 	      script {