fix(prom): missing callback attribute

apps/emqx_prometheus/src/emqx_prometheus.erl

@@ -90,8 +90,6 @@
 
 -define(HTTP_OPTIONS, [{autoredirect, true}, {timeout, 60000}]).
 
--define(LOGICAL_SUM_METRIC_NAMES, []).
-
 %%--------------------------------------------------------------------
 %% APIs
 %%--------------------------------------------------------------------
@@ -280,7 +278,7 @@ aggre_or_zip_init_acc() ->
     }.
 
 logic_sum_metrics() ->
-    ?LOGICAL_SUM_METRIC_NAMES.
+    [].
 
 %%--------------------------------------------------------------------
 %% Collector

apps/emqx_prometheus/src/emqx_prometheus_cluster.erl

@@ -38,6 +38,8 @@
 
 -callback aggre_or_zip_init_acc() -> map().
 
+-callback logic_sum_metrics() -> list().
+
 -define(MG(K, MAP), maps:get(K, MAP)).
 -define(PG0(K, PROPLISTS), proplists:get_value(K, PROPLISTS, 0)).