Remove space before a class_exists() check. Apparently there is an obscure PHP bug that can cause the check to fail with a fatal error, and some unconfirmed reports suggest that removing the space fixes it. I'm unconvinced, but adding this anyway as per user request.

See: https://bugs.php.net/bug.php?id=59298

git-svn-id: https://plugins.svn.wordpress.org/broken-link-checker/trunk@883094 b8457f37-d9ea-0310-8a92-e5e31aec5664