Implement "accept_config" attribute.

Refs #6191

lib/remote/apilistener-sync.cpp

@@ -158,6 +158,11 @@ Value ApiListener::ConfigUpdateHandler(const MessageOrigin& origin, const Dictio
 	if (!origin.FromZone || !Zone::GetLocalZone()->IsChildOf(origin.FromZone))
 		return Empty;
 
+	ApiListener::Ptr listener = ApiListener::GetInstance();
+
+	if (!listener || !listener->GetAcceptConfig())
+		return Empty;
+
 	Dictionary::Ptr update = params->Get("update");
 
 	bool configChange = false;

lib/remote/apilistener.ti

@@ -16,6 +16,8 @@ class ApiListener : DynamicObject
 		default {{{ return "5665"; }}}
 	};
 
+	[config] bool accept_config;
+
 	[state] double log_message_timestamp;
 
 	String identity;

lib/remote/remote-type.conf

@@ -31,6 +31,8 @@
 
 	%attribute %string "bind_host",
 	%attribute %string "bind_port",
+
+	%attribute %number "accept_config"
 }
 
 %type Endpoint {