w32: Also use _putenv_s for gnupg_unsetenv.
* common/sysutils.c (gnupg_setenv): Only enable use of _putenv_s with Security Feature in the CRT. (gnupg_unsetenv): Use _putenv_s when available.
- Signed-off-by: NIIBE Yutaka <email@example.com>
FWIW, we should anyway move on Widnows to the gpgrt provided setenv and getenv which are directly based on the W32API. The problem here is only that we have a lot of getenv in out code and need a wrapper. That wrapper would then also need to provide a static string as getenv does. A first step would be to wrap all getenv into gnupg-getenv calls.