replace deprecated mysql_query() with $wpdb->get_results()


git-svn-id: https://plugins.svn.wordpress.org/wp-users-exporter/trunk@1016082 b8457f37-d9ea-0310-8a92-e5e31aec5664
prevent warning message


git-svn-id: https://plugins.svn.wordpress.org/wp-users-exporter/trunk@1016085 b8457f37-d9ea-0310-8a92-e5e31aec5664
release version 1.4.1


git-svn-id: https://plugins.svn.wordpress.org/wp-users-exporter/trunk@1016088 b8457f37-d9ea-0310-8a92-e5e31aec5664