Set default PULL_PULL_SHA to branch name for periodic BMO e2e tests

Change-Id: I74aabc8f428f26900e7948fd7dafab7e40cba70e
Signed-off-by: Sunnatillo <sunnat.samadov@est.tech>
diff --git a/jjb/metal3/baremetal-operator/jjb-bmo-e2e.yaml b/jjb/metal3/baremetal-operator/jjb-bmo-e2e.yaml
index 3750f46..101cb76 100644
--- a/jjb/metal3/baremetal-operator/jjb-bmo-e2e.yaml
+++ b/jjb/metal3/baremetal-operator/jjb-bmo-e2e.yaml
@@ -68,6 +68,7 @@
         description: 'Ref name of the base branch'
     - string:
         name: PULL_PULL_SHA
+        default: '{BRANCH_NAME}' # Default set to branch name. This is needed when running periodic jobs
         description: 'Pull request head SHA'
     # End of Prow parameters
     - string: