Add a blank in the #! line for 4.2BSD Dynix etc.

From-SVN: r8894

gcc/config.sub

-#!/bin/sh
+#! /bin/sh
 # Configuration validation subroutine script, version 1.1.
 #   Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
 # This file is (in principle) common to ALL GNU software.