Accept RD_OPTION_* env variables from Rundeck

Change-Id: Ia31be0fc0667f0556c6e72a7d1e345924e993042
diff --git a/rundeck/client/runbook.yml b/rundeck/client/runbook.yml
index 27abaa6..a41481a 100644
--- a/rundeck/client/runbook.yml
+++ b/rundeck/client/runbook.yml
@@ -22,3 +22,5 @@
           public_keys:
             - key: ${_param:rundeck_runbook_public_key}
           user: ${linux:system:user:runbook}
+      accept_env:
+        - RD_OPTION_*