Call the thread cleanup code when requesting status

This ensures the correct number of connected clients is returned when
the status command is issued.

Previously the thread pool would only be cleaned up on a new connection.

src/server/serve.c

@@ -332,6 +332,8 @@ int server_count_clients( struct server *params )
 {
 	NULLCHECK( params );
 	int i, count = 0;
+	
+	cleanup_client_threads( params->nbd_client, params->max_nbd_clients );
 
 	for ( i = 0 ; i < params->max_nbd_clients ; i++ ) {
 		if ( params->nbd_client[i].thread != 0 ) {