Update ops_from_code.yaml

ops_stations/ops_from_code.yaml

@@ -241,7 +241,7 @@ resources:
           template: linux_opstation_RAND
           params:
             RAND: { get_resource: rand_string }
-      image: ubuntu_18.04_vta
+      image: ubuntu_18.04.4_vta
       flavor: cy.xlarge
       networks:
         - port: { get_resource: linux_opstation_port }