Fix segfault
Fix segfault

Apparently, g_io_channel_unref() was called twice: once in the
menu-cache's on_client_closed() callback and once from the finalize
function, g_io_unix_finalize()/g_io_win32_finalize(), which is called
anyway when the source is removed.

Signed-off-by: Laurentiu Palcu <16abc73369dc7d9b0ad84a33cb34892350afc125@intel.com>

lxde/menu-cache,lxde/menu-cache