fix CPAN bootstrap test to work with new CPAN.pm versions

New CPAN.pm versions have a setting pushy_https, which overrides the URL
list to always be www.cpan.org, if it thinks using https is possible.
We're trying to use a local generated mirror, so the setting needs to be
turned off so our urllist is respected.

Author: haarg

xt/cpan-bootstrap.pl

@@ -31,6 +31,7 @@
   urllist      => ["$url"],
   install_help => 'manual',
   check_sigs   => 0,
+  pushy_https  => 0,
   shell        => (
     $^O eq 'MSWin32' ? ($ENV{COMSPEC} || 'cmd.exe')
                      : ($ENV{SHELL}   || '/bin/sh')