Fix zts build on PHP5.6 :]
Merge pull request #663 from bjori/php-master-fix

Fix zts build on post PHP5.6 versions :]

* bjori/php-master-fix:
  Fix zts build on PHP5.6 :]
Merge branch 'v1.5'

* v1.5:
  Fix zts build on PHP5.6 :]