[stable/zed] chore: use git ref for neutron-vpnaas (#1466)

relate to #1458

Reviewed-by: Mohammed Naser <mnaser@vexxhost.com>
diff --git a/images/neutron/Dockerfile b/images/neutron/Dockerfile
index 4eb1d5c..965f0ee 100644
--- a/images/neutron/Dockerfile
+++ b/images/neutron/Dockerfile
@@ -7,7 +7,8 @@
 ARG NEUTRON_GIT_REF=ece6a9a7acab20d5a39f54784427258d54b72cfd
 ADD --keep-git-dir=true https://opendev.org/openstack/neutron.git#${NEUTRON_GIT_REF} /src/neutron
 RUN git -C /src/neutron fetch --unshallow
-ADD --keep-git-dir=true https://opendev.org/openstack/neutron-vpnaas.git#unmaintained/zed /src/neutron-vpnaas
+ARG NEUTRON_VPNAAS_GIT_REF=45d63e1e9adc2b3ce4e3b2b5728744f99ea70a97
+ADD --keep-git-dir=true https://opendev.org/openstack/neutron-vpnaas.git#${NEUTRON_VPNAAS_GIT_REF} /src/neutron-vpnaas
 RUN git -C /src/neutron-vpnaas fetch --unshallow
 ARG POLICY_SERVER_GIT_REF=4a86b140d5510823a8fb8a59137feddf5b111b26
 ADD --keep-git-dir=true https://github.com/vexxhost/neutron-policy-server.git#${POLICY_SERVER_GIT_REF} /src/neutron-policy-server