Fix restoring CPPFLAGS

configure.ac

@@ -3454,8 +3454,8 @@ then
 	AC_CHECK_HEADERS([Python.h],[have_python_h=yes],[have_python_h=no])
 	if test "$have_python_h" = "no" ; then
 		AC_MSG_ERROR([Python.h missing, cannot build StarPU python interface (consider installing python-dev)])
-		CPPFLAGS=${SAVED_CPPFLAGS}
 	fi
+	CPPFLAGS=${SAVED_CPPFLAGS}
 	AC_MSG_CHECKING(for python3 module joblib)
 	AC_PYTHON_MODULE(joblib,[joblib_avail=yes],[joblib_avail=no])
 	AC_MSG_RESULT($joblib_avail)