avoid letting winpthread's pthread.h include our own config.h...

include/starpu_util.h

@@ -310,6 +310,7 @@ double starpu_timing_now(void);
 #endif
 #include <time.h>
 #if !defined(_MSC_VER) || defined(BUILDING_STARPU)
+#undef HAVE_CONFIG_H
 #undef HAVE_STRUCT_TIMESPEC
 #include <pthread.h>
 #endif