Fix Linting Error

The value of the async key was copied from the synapse configuration side so hopefully it works.

roles/custom/matrix-bot-draupnir/defaults/main.yml

@@ -148,17 +148,14 @@ matrix_bot_draupnir_synapse_http_antispam_config_base_url: "{{ matrix_bot_draupn
 # Therefore the module is configured from Draupnir because the consumer of the module determines what settings are relevant.
 
 matrix_bot_draupnir_synapse_http_antispam_config_enabled_callbacks:
-  #- check_event_for_spam
   - user_may_invite
   - user_may_join_room
 
 matrix_bot_draupnir_synapse_http_antispam_config_fail_open:
-  #check_event_for_spam: true
   user_may_invite: true
   user_may_join_room: true
 
-matrix_bot_draupnir_synapse_http_antispam_config_async:
-  #check_event_for_spam: true
+matrix_bot_draupnir_synapse_http_antispam_config_async: {}
 
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.