fix(gw): compatible with the max_connection is string type

apps/emqx_connector/src/emqx_connector_redis.erl

@@ -90,7 +90,6 @@ fields(sentinel) ->
         }},
         {sentinel, #{
             type => string(),
-            required => true,
             desc => ?DESC("sentinel_desc")
         }}
     ] ++

apps/emqx_gateway/src/emqx_gateway_api_listeners.erl

@@ -304,7 +304,8 @@ do_listeners_cluster_status(Listeners) ->
                 Id => #{
                     node => Node,
                     current_connections => Curr,
-                    max_connections => Max
+                    %% XXX: Since it is taken from raw-conf, it is possible a string
+                    max_connections => int(Max)
                 }
             }
         end,
@@ -312,6 +313,11 @@ do_listeners_cluster_status(Listeners) ->
         Listeners
     ).
 
+int(B) when is_binary(B) ->
+    binary_to_integer(B);
+int(I) when is_integer(I) ->
+    I.
+
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