fix compilation warnings of unused variables
diff --git a/src/fabric_db_update_listener.erl b/src/fabric_db_update_listener.erl
index ba9111d..733be89 100644
--- a/src/fabric_db_update_listener.erl
+++ b/src/fabric_db_update_listener.erl
@@ -85,7 +85,7 @@
     {ok, St};
 handle_db_event(_DbName, deleted, St) ->
     {stop, St};
-handle_db_event(DbName, Event, St) ->
+handle_db_event(_DbName, _Event, St) ->
     {ok, St}.
 
 start_cleanup_monitor(Parent, Notifiers) ->