remove -U_FORTIFY_SOURCE from cmake

[PetrusZ]

https://github.com/FDH2/UxPlay/blob/66f92b065944a29f4ce95426a69ff91f07534b9f/lib/CMakeLists.txt#L19

FORTIFY_SOURCE is a GCC and GLIBC security feature that attempts to detect certain classes of buffer overflows. Its enabled by default on most Linux platforms.

It can be turned off with -D_FORTIFY_SOURCE=0 or -U_FORTIFY_SOURCE. However, its usually not appropriate to disable FORTIFY_SOURCE in production software.

I did a basic test, after removing -U_FORTIFY_SOURCE, uxplay builds success and it is running normally too.

See also:

1. https://bugs.gentoo.org/889044 (detail is in the attachment)
2. https://stackoverflow.com/tags/fortify-source/info

[fduncanh]

OK I removed --U_FORTIFY_SOURCE and re-released 1.61 as 1.61.1

If necessary I'll release it as 1.62 later if 1.61.1 messes up Arch or Debian releases

[PetrusZ]

Thank you, again!