chore(mqtt-connector): refine logging level

connect failure should be at warning level but not error,
the connecting state is visiable from dashbaord
also the resource manager logs connection failures in general
at warning level

apps/emqx_connector/src/mqtt/emqx_connector_mqtt_worker.erl

@@ -202,13 +202,13 @@ connect(Name) ->
                     Error
             end;
         {error, Reason} = Error ->
-            ?SLOG(error, #{
+            ?SLOG(warning, #{
                 msg => "client_connect_failed",
-                reason => Reason
+                reason => Reason,
+                name => Name
             }),
             Error
     end.
-
 subscribe_remote_topics(Ref, #{remote := #{topic := FromTopic, qos := QoS}}) ->
     emqtt:subscribe(ref(Ref), FromTopic, QoS);
 subscribe_remote_topics(_Ref, undefined) ->