update link to old PHP reference

Author: zackse

testing-with-tap/php.md

@@ -8,6 +8,6 @@ title: Testing with PHP
 
 ## Links
 
--    [Using Test::Harness](http://search.cpan.org/~petdance/Test-Harness-2.64/lib/Test/Harness/TAP.pod#PHP)
+-    [Using Test::Harness](https://github.com/Perl-Toolchain-Gang/Test-Harness/blob/master/reference/Test-Harness-2.64/lib/Test/Harness/TAP.pod#php)
 -    [TAP based PHP testing presentations from ApacheCon and OSCon](http://www.modperlcookbook.org/~geoff/)
 -    [Test::Simple & Test::More for PHP](http://code.google.com/p/test-more-php/)