Updated infra pods namespace for periodic-voltha-test-bbsim and periodic-multiple-olts-test-bbsim jobs

Change-Id: Icd8ce9f4de0ba8dfd5fe1936655244a3dbc294af
diff --git a/jjb/pipeline/voltha-nightly-tests-bbsim.groovy b/jjb/pipeline/voltha-nightly-tests-bbsim.groovy
index 5fb1278..d86aac9 100644
--- a/jjb/pipeline/voltha-nightly-tests-bbsim.groovy
+++ b/jjb/pipeline/voltha-nightly-tests-bbsim.groovy
@@ -103,6 +103,7 @@
              echo "on branch: ${branch}, sourcing kind-voltha/releases/${branch}"
              source "$WORKSPACE/kind-voltha/releases/${branch}"
            else
+             export INFRA_NS="infra"
              echo "on master, using default settings for kind-voltha"
            fi