Make sure legacy rabbit_management_load_definitions step does not block boot

Follow-up to #2656, #2384.

Author: michaelklishin

deps/rabbitmq_management/src/rabbit_mgmt_app.erl

@@ -24,8 +24,7 @@
 
 -rabbit_boot_step({rabbit_management_load_definitions,
                    [{description, "Imports definition file at management.load_definitions"},
-                    {mfa,         {rabbit_mgmt_load_definitions, boot, []}},
-                    {enables,     empty_db_check}]}).
+                    {mfa,         {rabbit_mgmt_load_definitions, boot, []}}]}).
 
 start(_Type, _StartArgs) ->
     case application:get_env(rabbitmq_management_agent, disable_metrics_collector, false) of