Drop the old perl start magic and replace it with a normal shebang

perlrun(1) leads the way.
Reviewed-by: NMatt Caswell <matt@openssl.org>

Configure

+#! /usr/bin/env perl
 # -*- mode: perl; -*-
-:
-eval 'exec perl -S $0 ${1+"$@"}'
-    if $running_under_some_shell;
+
 ##
 ##  Configure -- OpenSSL source tree configuration script
 ##  If editing this file, run this command before committing