php56-mysqlnd_ms: update to 1.5.2, patch for PHP 5.6
php56-mysqlnd_ms: update to 1.5.2, patch for PHP 5.6

Closes #1573.

TomK/homebrew-php,ablyler/homebrew-php,dguyon/homebrew-php,mkalkbrenner/homebrew-php,philcook/homebrew-php