package/x11r7/xlib_libXcursor: security bump to version 1.1.15

Fixes CVE-2017-16612:
https://lists.x.org/archives/xorg-announce/2017-November/002823.html



Added all hashed provided by upstream.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>