Incorrect function check

git-svn-id: https://plugins.svn.wordpress.org/mycred/trunk@765499 b8457f37-d9ea-0310-8a92-e5e31aec5664
Improved default rank check.

git-svn-id: https://plugins.svn.wordpress.org/mycred/trunk@765500 b8457f37-d9ea-0310-8a92-e5e31aec5664