Arthur: update tf-sync-repos.yaml

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: I2817e976667c969f9fac2b335d24a5505c2aaf58
diff --git a/tf-sync-repos.yaml b/tf-sync-repos.yaml
index fd7ccc6..a13b06a 100644
--- a/tf-sync-repos.yaml
+++ b/tf-sync-repos.yaml
@@ -28,8 +28,8 @@
             url: https://review.trustedfirmware.org/${GERRIT_PROJECT}
             refspec: ${GERRIT_REFSPEC}
             branches:
-                - origin/master
-            skip-tag: false
+                - ${GERRIT_BRANCH}
+            skip-tag: true
             clean:
                 before: true
             choosing-strategy: gerrit