Forward port 2.8 fix.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63085 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

distrib/scripts/mac/lipo-dir.py

@@ -24,6 +24,8 @@ def lipo_walker(data, dirname, names):
                 print "Successfully created %s" % outputfile
         else:
             if os.path.islink(fullpath):
+                if os.path.exists(outputfile):
+                    os.remove(outputfile)
                 linkto = os.readlink(fullpath)
                 
                 if linkto.startswith(ppc_basedir):