Fix linux.system.repo.grafana class
diff --git a/linux/system/repo/grafana.yml b/linux/system/repo/grafana.yml
index 267065e..c1c8a5b 100644
--- a/linux/system/repo/grafana.yml
+++ b/linux/system/repo/grafana.yml
@@ -1,7 +1,8 @@
+parameters:
   linux:
     system:
       repo:
         grafana:
           enabled: true
           source: 'deb https://packagecloud.io/grafana/stable/debian/ jessie main'
-          key_url: 'https://packagecloud.io/gpg.key'
\ No newline at end of file
+          key_url: 'https://packagecloud.io/gpg.key'