Only "notify" if "exec" will run (fixes frankiethekneeman#36)

manifests/runner.pp

@@ -416,7 +416,9 @@
     $kubernetes_opts="${kubernetes_host_opt} ${kubernetes_cert_file_opt} ${kubernetes_key_file_opt} ${kubernetes_ca_file_opt} ${kubernetes_image_opt} ${kubernetes_namespace_opt} ${kubernetes_priviledged_opt} ${kubernetes_cpus_opt} ${kubernetes_memory_opt} ${kubernetes_service_cpus_opt} ${kubernetes_service_memory_opt}"
 
     $opts = "${runner_opts} ${executor_opt} ${docker_opts} ${parallels_vm_opt} ${ssh_opts} ${machine_opts} ${kubernetes_opts}"
-    notify{"Will run gitlab-ci-multi-runner register --non-interactive ${opts}": }
+    notify{ "Will run gitlab-ci-multi-runner register --non-interactive ${opts}": 
+        onlyif => "! grep ${node_description} ${::gitlab_ci_multi_runner::toml_file}",
+    }
 
     # Register a new runner - this is where the magic happens.
     # Only if the config.toml file doesn't already contain an entry.