Include sys/wait.h only on unix-like systems
Include sys/wait.h only on unix-like systems

MinGW installation doesn't contain sys/wait.h. Usage of functions
from sys/wait.h is already guarded by the same #ifdef dirictive.

mpreisler/openscap,jan-cerny/openscap,mpreisler/openscap,OpenSCAP/openscap,jan-cerny/openscap,OpenSCAP/openscap,redhatrises/openscap,OpenSCAP/openscap,redhatrises/openscap,redhatrises/openscap,jan-cerny/openscap,mpreisler/openscap,OpenSCAP/openscap,mpreisler/openscap,redhatrises/openscap,jan-cerny/openscap,jan-cerny/openscap,redhatrises/openscap,redhatrises/openscap,OpenSCAP/openscap,jan-cerny/openscap,OpenSCAP/openscap,mpreisler/openscap,mpreisler/openscap