Minor: remove unused variable

git-svn-id: https://plugins.svn.wordpress.org/broken-link-checker/trunk@1025680 b8457f37-d9ea-0310-8a92-e5e31aec5664
Minor: various cleanup.

git-svn-id: https://plugins.svn.wordpress.org/broken-link-checker/trunk@1025688 b8457f37-d9ea-0310-8a92-e5e31aec5664