Draft: Enable Loki as a replacement for Elasticsearch when `enable_loki` is set.

Note, it is not possible to have both Loki and Elasticsearch enabled, so enable_elasticsearch must be disabled, when enable_loki is enabled.

roles/log-collector/templates/rsyslog-collector.conf.j2

@@ -40,6 +40,9 @@ template(name="TmplFile" type="list"){
 # if elasticsearch is disabled, and loki is enabled, then we setup loki templates
 # if elasticsearch is enabled, but loki is also enabled, then only ES is enabled
 {% if enable_loki %}
+module(
+  load="omhttp"
+)
 template(name="lokiTemplate"
          type="list" ) {
            constant(value="{")