[TF] change VSRX image to be suitable for EU cloud

PRODX-3815

Change-Id: Ifb11a71b7832fd8f60c9ef23b4a535a04c3f270d
diff --git a/de/heat-templates/fragments/NetworkPrvFlVSRX.yaml b/de/heat-templates/fragments/NetworkPrvFlVSRX.yaml
index 5ba7015..b8b63b5 100644
--- a/de/heat-templates/fragments/NetworkPrvFlVSRX.yaml
+++ b/de/heat-templates/fragments/NetworkPrvFlVSRX.yaml
@@ -50,7 +50,7 @@
     properties:
       name: { list_join: ['-', [get_param: "OS::stack_name", 'vsrx01']] }
       availability_zone: nova
-      image: vsrx-mcp2-external
+      image: vsrx-mcp2-tf
       flavor: oc_vsrx
       networks:
         - port: { get_resource: accessible_server_port }