handshake.c: minor changes to switch

 * After parsing HTTP_ISSUING_FILE -> read_ok (return 0)

TODO:

 * We lws_alloate_header_table *again* in lws_handshake_server for keep-alives. Is this the right place?
 * What is the proper handling for HTTP_ISSUING_FILE in the context of libwebsocket_read?
Whoops should've been lumped in with previous commit:
    handshake.c: minor changes to switch

     * After parsing HTTP_ISSUING_FILE -> read_ok (return 0)