Fix syntax

tasks/main.yml

@@ -25,7 +25,7 @@
 
     - name: Import elasticsearch
       import_tasks: elasticsearch.yml
-      when: groups['logserver'] is defined and inventory_hostname in groups['logserver'] and elasticsearch_install|default(yes)
+      when: groups['logserver'] is defined and inventory_hostname in groups['logserver'] and elasticsearch_install|default('yes')
 
     - name: Import haproxy
       import_tasks: haproxy.yml