Broker will return CONNACK rc=5 when a client is not authorised.

This was being incorrectly set as rc=4.

ChangeLog.txt

@@ -9,6 +9,8 @@ Broker:
 - ACLs are now checked before sending a will message.
 - Fix possible crash when using bridges on Windows. Closes #465384.
 - Fix parsing of auth_opt_ arguments with extra spaces/tabs.
+- Broker will return CONNACK rc=5 when a username/password is not authorised.
+  This was being incorrectly set as rc=4.
 
 Client library:
 - Inflight message count wasn't being decreased for outgoing messages using

src/read_handle_server.c

@@ -366,7 +366,7 @@ int mqtt3_handle_connect(struct mosquitto_db *db, struct mosquitto *context)
 				case MOSQ_ERR_SUCCESS:
 					break;
 				case MOSQ_ERR_AUTH:
-					_mosquitto_send_connack(context, 0, CONNACK_REFUSED_BAD_USERNAME_PASSWORD);
+					_mosquitto_send_connack(context, 0, CONNACK_REFUSED_NOT_AUTHORIZED);
 					mqtt3_context_disconnect(db, context);
 					rc = 1;
 					goto handle_connect_error;