fix class registration

Noticed using reflection

    $ php --re swoole | grep Class
    - Classes [9] {
    Class [ <internal:swoole> class swoole_server ] {
    Class [ <internal:swoole> class swoole_lock ] {
    Class [ <internal:swoole> class swoole_process ] {
    Class [ <internal:swoole> class swoole_buffer ] {
    Class [ <internal:swoole> class swoole_client ] {
    Class [ <internal:swoole> <iterateable> class swoole_table implements Iterator, Traversable, Countable ] {
    Class [ <internal:swoole> class swoole_http_server extends swoole_server ] {
    Class [ <internal:swoole> class swoole_http_response ] {
    Class [ <internal:swoole> class (null) ] {

=> last one have no name, so is very probably unusable