Fix database upgrade process

git-svn-id: https://plugins.svn.wordpress.org/broken-link-checker/trunk@1032569 b8457f37-d9ea-0310-8a92-e5e31aec5664
Version 1.10.1

git-svn-id: https://plugins.svn.wordpress.org/broken-link-checker/trunk@1032571 b8457f37-d9ea-0310-8a92-e5e31aec5664