Only set alerting if variable is false (#112)

* Only set alerting if variable is false

The current configuration template doesn't allow for disabling the alerting. It is enabled by default. This small patch makes sure we can disable the alerting.

* implement use of 'if not' conditional

Author: Wout van Heeswijk

templates/grafana.ini.j2

@@ -96,9 +96,9 @@ enabled = true
 path = {{ grafana_data_dir }}/dashboards
 
 # Alerting
-{% if grafana_alerting %}
+{% if not grafana_alerting %}
 [alerting]
-enabled = True
+enabled = false
 ;execute_alerts = true
 {% endif %}