Update arthur-sync-qa-tools.yaml

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: I4d6e6a53332d585208025d8a017a2f8432bd1459
diff --git a/arthur-sync-qa-tools.yaml b/arthur-sync-qa-tools.yaml
index b893c32..848d29a 100644
--- a/arthur-sync-qa-tools.yaml
+++ b/arthur-sync-qa-tools.yaml
@@ -39,6 +39,7 @@
     builders:
       - shell: |-
           #!/bin/bash
+          set -x
 
           SSH_PARAMS="-o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o PubkeyAcceptedKeyTypes=+ssh-rsa -p 29418 -i ${CI_BOT_KEY}"
           host=${GERRIT_PROJECT#*://}
@@ -54,4 +55,4 @@
           echo "Fetch ${GITLAB_REPO}:${SYNC_BRANCH}"
           git -C "${_workdir}" fetch ${GITLAB_REPO} ${SYNC_BRANCH}
           echo "Sync to ${GERRIT_PROJECT}"
-          GIT_SSH_COMMAND="ssh ${SSH_PARAMS}" git -C "${_workdir}" push ${REPO_SSH_URL} ${SYNC_BRANCH}
+          GIT_SSH_COMMAND="ssh ${SSH_PARAMS}" git -C "${_workdir}" push ${REPO_SSH_URL} FETCH_HEAD:refs/heads/${SYNC_BRANCH}