fix SHELLY_LISP_BINARY for Cygwin
fix SHELLY_LISP_BINARY for Cygwin

*current-lisp-path* return path divided by "\" on Windows.
but Cygwin require divided by "/".

qyqx/shelly,fukamachi/shelly,qyqx/shelly,qyqx/shelly,fukamachi/shelly