package/ghostscript: add upstream security fixes

CVE-2019-6116: Remote code execution.

https://www.openwall.com/lists/oss-security/2019/01/23/5



Cc: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>