[toddlers] Remove the principal config variable

I didn't realized that openshift will still process all the templates variables
even if they are commented out.

Signed-off-by: Michal Konecny <mkonecny@redhat.com>

roles/openshift-apps/toddlers/templates/fedora-messaging.toml

@@ -211,7 +211,6 @@ profile = "stg"
 {% else %}
 profile = "koji"
 {% endif %}
-#principal = {{service}}/{{host}}
 keytab = /etc/keytabs/service.keytab
 
 # Configuration section for scm_request_processor