Arthur: update tf-sync-repos.yaml

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: Ic6107c7a19a60456b42a562431fc1256d210d06f
diff --git a/tf-sync-repos.yaml b/tf-sync-repos.yaml
index 53db54f..448da94 100644
--- a/tf-sync-repos.yaml
+++ b/tf-sync-repos.yaml
@@ -7,7 +7,7 @@
     disabled: false
     builders:
     - shell: |-
-        #!/bin/bash -e
+        #!/bin/bash -xe
 
         echo ""
         echo "########################################################################"
@@ -26,10 +26,9 @@
     scm:
         - git:
             url: https://review.trustedfirmware.org/${GERRIT_PROJECT}
-            refspec: ${GERRIT_REFSPEC}
             branches:
-                - ${GERRIT_BRANCH}
-            skip-tag: true
+                - origin/master
+            skip-tag: false
             clean:
                 before: true
             choosing-strategy: gerrit