probable fix: stay consistent and always return bytes from _read().
probable fix: stay consistent and always return bytes from _read().

even if we are in non-blocking mode:
still return a byte value (b'') from _read in the case we get a EWOULDBLOCK.

otherwise returns None -> error in read_request() when joining the read values.

kaji-project/shinken-mod-livestatus,shinken-monitoring/mod-livestatus,shinken-monitoring/mod-livestatus,kaji-project/shinken-mod-livestatus,staute/shinken-mod-livestatus,staute/shinken-mod-livestatus