Change config.h to compile isatty() and getpid() on macOS when -DCMAKE_CXX_STANDARD=98

include/exiv2/config.h

@@ -95,9 +95,9 @@ typedef int pid_t;
 
 // https://softwareengineering.stackexchange.com/questions/291141/how-to-handle-design-changes-for-auto-ptr-deprecation-in-c11
 #include <memory>
+#include <sys/types.h>
+#include <unistd.h>
 #if __cplusplus >= 201103L
-  #include <sys/types.h>
-  #include <unistd.h>
   template <typename T>
   using auto_ptr = std::unique_ptr<T>;
 #else